Actually, Electrum will accept that decoder's "Parsed Result", it's basically what Electrum decodes when it scan the QR code. (try it)

You're probably talking about the "Raw bytes HEX" in the result of zxing decoder, it doesn't work because Electrum is expecting a serialized signed raw transaction if provided a hex string in its "Load transaction" menu.
That hex string in zxing's result is the raw bytes interpretation of the Base43 string contained in the QR code;
In simple words, it represents those letters, numbers and signs, not the transaction itself.

Besides, electrum43 tool is 8years old, in modern Electrum versions, it'll only work on fully signed Electrum transaction's QR codes.
The (unsigned) PSBT's QR Code when decoded into hex string is be incompatible with Electrum (since v4.0.1 - July 2020) since it's expecting either a Base64 or Base43 PSBT string or a RAW PSBT file. (reference)
So, in terms of use-case, that tool is pretty unnecessary since she can only use it at the last step,
The PSBT will have to be transmitted by other means like the simple but effective PSBT file/text method, or find a solution to the webcam. (if it became an issue)

The last two are actually reversed.

Using a commercial hardware wallet is at intermediate level for its ease of use,
and it may not even be "Air-Gap" depending on the hardware device's source code availability.

On the other hand, USB stick with Tails require expertise to properly utilize a wallet's cold-storage feature
but the end result is as safe (if not better) as the most reputable hardware wallet out there.

Using Bitcoin Core?
Set the provided args in the third option in this official documentary for Bitcoin Core client: https://github.com/bitcoin/bitcoin/blob/master/doc/tor.md#3-manually-create-a-bitcoin-core-onion-service
Most importantly, the --externalip that you can get from "C:/Tor/tor/hidden_service_directory/hostname" based from the "HiddenServiceDir" that you've set in your torrc file.

This is one of Mycelium's feature that derives all of the three common script types from each of your account_index.
All of which should be recoverable from the seed phrase.

No, this is just one of the basic privacy feature of most self-custodial wallets.
The address changes in every transaction to avoid address reuse, but all of those belong to the same "external_chain" derivation path.
When being restored to other wallets, all of the previously used and future addresses will be restored if the path is correct.

That section shows all of the available UTXO of the currently loaded Mycelium account.
Not necessarily means the balance of the currently displayed address but of any address related to its derivation path.
So, for example: if you've successfully restored the seed phrase and the wallet contains the currently displayed address, it should also show those UTXOs, thus the correct balance.

That derivation path indicates that it's the address of your first 'account_index' (m/49'/0'/0') and it's your third receiving address (../0/2).

Given all of the provided information (review):

• The active Mycelium account is "Account 1"
• The UTXOs are showing when that account is active and the addresses shown are P2SH-SegWit.
• The displayed address of the same script type's derivation path is m/49'/0'/0'/0/2.

The solid conclusion is:

• The derivation when restoring it to Electrum should be m/49h/0h/0h but that's the P2SH-SegWit default and should've been "seen" by "detect existing account" button.
  So, it's either the seed phrase is actually wrong (for your other wallet) or you've set a passphrase in Mycelium which is available if you chose 'Restore' instead of 'Create' in the initial setup.
  In case of inclusion of a passphrase, tick "Extend this seed with custom words" in Electrum and type your Passphrase when prompted.
  
  Unfortunately, I can't add anything to help you with the PIN issue.

The best clue is the error he got from Bitaddress.

I tried to reproduce it with private key 0's WIF format and the result is positive,
I've also tried other invalid private keys and the errors aren't the same (the site is surprisingly specific).

Other clues are just from Electrum's behavior to check for the provided private key's validity and OP's statement that the WIF private key is in the correct format.
So at that point, I'm 75% confident that it's his private key.

Or his granpa used a bugged wallet that produced that private key
IIRC, there was a old wallet that had an issue that made it generate that private key pretty consistently, but I can't remember where I read that.

Or this is just another one of the "usual" can't recover old bitcoin topic.

Thought you said that you can access the 'Balance' tab to see your UTXOs in the previous reply?
If that's the case, the 'Accounts' tab should also be accessible, unless you've locked the tab by clicking that "lock" icon once.
If you did, then you're up to a lot of guesswork and the only reliable method left is to get through the PIN.

Without info from the Accounts tab, try to edit the derivation path when restoring it to Electrum.
After selecting "P2SH-SegWit" script type (based from your description, don't skip this), edit the derivation path m/49h/0h/0h below into:

• m/49h/0h/1h
• m/49h/0h/2h
• m/49h/0h/3h
• ... And so on.

For the record, you haven't mentioned that the accounts tab is locked and it's not locked by default even after setting a PIN.

---

-edit-
You can still get a small hint of the derivation path in the Balance tab: The currently active account name should be the one displayed above the address.
If it's not renamed, the name should indicate its account number;
Translate that to derivation path: Account 1 = m/49h/0h/0h, Account 2 = m/49h/0h/1h, Account 3 = m/49h/0h/2h...

The UTXO from your unspent outputs list should belong to the current selected account where the address shown belongs to.

Enable "Settings->Show address path" to see the address' derivation path.
Wallets like Electrum use the path through the account_index during restore (like in my examples, the symbol ' is equal to h).

The "Bitcoin SA" Account that I've mentioned and those Account 2 mentioned in their help window can be created anytime after the initial setup.

You can easily check those by looking at the types of the accounts listed in your 'Accounts' tab.
The accounts created right after the initial setup is the first account under "Bitcoin HD (<number of accounts>)" and "Ethereum" for altcoins (leave it since it's unrelated),
If you see another account under "Bitcoin HD" that's not generated when you created the wallet but created sometime after it.
And depending on its type, you may have to edit specific settings when restoring the wallet to another client or it may require a different backup to restore like for SA (Single Address) account.

So the info you need from the accounts tab are: find the specific account where the balance are from and tell the account's type,
e.g.: "Bitcoin HD", Account 2 (might have been renamed but the sorting still follows the account number), contains n private keys.

Now, if it's in your first Bitcoin HD account and the seed phrase isn't restoring the same addresses.
Then there's a high chance that you might have stored the wrong seed phrase
and since you said you haven't done anything different, it may not be a case of wrong passphrase.

Is your granpa's private key: 5HpHagT65TZzG1PH3CSu63k8DbpvD8s5ip4nEB3kEsreAbuatmU?
Because that's one of the invalid Bitcoin private keys out of valid range, specifically private key 0x00.
Thought so because of Bitaddress' error message.

And since it's outside range, that's invalid despite being a correctly constructed WIF private key.

Is there a chance that you've setup an "SA account" in Mycelium?
If the balance belongs there ('Accounts' tab->Bitcoin SA), it wont be restored by your backup seed phrase since its private key is randomly generated and unrelated.

Other than that, some common possible restore-related issue are already covered by their in-app help menu in: "Settings->Help->Missing Transactions".

This is a reckless advice because you are already aware that there's an issue when he tried to restore his backup.
Clearing the app's data will essentially delete his wallet so with the current issue, he'll lose his only chance in case that the wallet is unrelated to that seed phrase.
But he can safely clear its "cache" to see if it's the one causing the PIN issue.

This won't work in the other party's advantage since Royal Mail doesn't support Bitcoin payment as COD.
Everything should be coordinated between you and the seller, if there's an escrow, make sure that it's reputable (you can tell the name for us to check)
Either the seller is taking the risk or has "another plan".

Be careful since a scammer can still pull-off various "parcel scams" by saying that as a front.
And depending on the contents of the parcel, they may try to trick you that it's confiscated and demand you payment in cryptocurrencies to release it.

Just make sure to track it using their official tracking website and not the link sent by the seller.

It's just in simple json format.
For wallet, simply type your wallet file names exactly like this (except the exact wallet's name);
For one wallet:
For two or more wallets:

The gist is, if there's two or more wallets, put a "," sign after the wallet name, if it's the last/single wallet, do not include a ",".
The "wallet name" are the folders you can find inside "wallets" directory, add the quotation marks as shown in the examples.

That'll work assuming that every setting is set correctly and chainstate & blocks folders are intact.

I assume that when you try to load the wallet files which are auto-unloaded by the blank "settings.json" file, your pruned node asked for --reindex which triggers the IBD.
Also, you might have set some incompatible settings in the GUI before, that you haven't set in the new install, specially: "Prune block storage" settings.
If so, you can re-initialize Bitcoin Core with: $ bitcoin-qt --choosedatadir set your previous settings and point it to your data directory.
Alternatively, set your previous settings to your bitcoin.conf file.

Have you checked all of the letters and numbers and not just the first and last characters?
Because a malware/virus can easily generate a similar address and replace the one in your clipboard when you copy/paste.

Contact the recipient and instruct him to check the address that he have sent you if it belongs to his wallet.
Same as my previous recommendation, check all of the characters.
Now if everything checks out and you're positive that he's telling the truth, he must contact the exchange/custodial wallet provider where he told you to send the bitcoins.

If it's not an exchange/custodial wallet, then his transaction that spent your transaction's output indicates that he already spent it or someone else did. (e.g. his wallet was hacked)
But your end of the deal is to send to his provided address (which you did) and you can prove it with that TXID, whatever the reason is, the rest is on him.

As for the address: bc1qzgga4qteepkvr79ulka5f3luqdvc9y03r363f0,
the behavior is odd for an exchange deposit address where its coins are usually consolidated with other users' bitcoins after some time.
In that address' case, it's sent to another address before getting consolidated to a legacy address.
(not a strong evidence, though)

Not the OP, but it's probably Youtube and that's how Google recommend videos when a user search for guides.
"The highly-viewed/liked videos are better", their search engine thinks.

With that, a noob's gonna be noob to search "easy-to-follow" videos than research from official and reputable guides.

(I doubt that he even read the posts in this thread based from his last login date, maybe the first two replies since it already answered his query)

All Cold-storage setup tutorials tell you to create the wallet in the air-gap device, so in the process, the seed phrase and passphrase are kept "cold" as well.
That makes it "Cold", unless you "accidentally" store it on an online machine.

If you're going for Tails setup, its "Persistent Storage" where you should put the cold-storage wallet's data directory
can be encrypted with a password of your choice, every other generated files will automatically be forgotten in every session.
With that, set a strong persistent storage encryption password (different from your wallet's password and seed phrase's passphrase)
So even if the flash drive is stolen, the thief wont be able to access its contents.

It'll be unnecessary because AFAIK, there are already about 5 topics there that tackled that issue ever since seed type selection was removed in the GUI.
Example: Electrum 4.1.0 released - Feature discussion & other related issues.

There's just a bit of difference in Electrum make_seed command's named arguments that wont work in electrum-ltc but it's basically the same.

I don't know why you chose to reply to those particular replies but it's "not great" since it misleading actually.

-The coinbase transaction's hash doesn't represent POW or timestamp aside from the HASH256 (SHA256 x2) hash of its serialized transaction data.
Its TXID is the same for legacy, but for for SegWit, the Witness data are excluded when hashing. Both should be in little-endian order.
There's no timestamp in a coinbase transaction or "POW Data" whatever that means,
Perhaps she's talking about the timestamp in the "block header" and the block header's hash which are related in mining.

-It's part of the Bitcoin protocol which is the only requirement to tell "where the coins came from" is if it's in the first transaction of the block indicating that it's a coinbase input, it's valid as long as it's in a valid block and not breaking any consensus rules.

Read this to see what's in a coinbase transaction: https://learnmeabitcoin.com/technical/mining/coinbase-transaction/#

At least you've read actual good replies from other members already.

The exception error (enclosed in brackets) should be the literal description of the error.
In your case, Electrum cannot parse the PSBT in Blue Wallet's QR Code.

Notice that Blue Wallet's QR is animated (URv1 or URv2 QR code)?
Electrum doesn't support such QR code.
You can follow this issue to see if it will be implemented in the future: https://github.com/spesmilo/electrum/issues/7905

For now, I'd suggest to use Electrum as watching-only wallet for compatibility, its new Android version's GUI is better than the previous IMO.

I guess instructions in plain words wont cut it, here's some screenshots of the steps:

• Create a new standard seed via console and copy it on a piece of paper:
  Obviously, do not use the seed phrase shown in your screenshot or this screenshot since everyone saw it already.
  
• Create a new wallet by selecting these options; in the wallet creation 'install Wizard', type your preferred wallet name and click 'Next':
  
• Select "Standard wallet" for the wallet type.
  
• Select "I already have a seed" for the seed option:
  
• Type the seed phrase that you've created in the console.
  

Also, it's much safer if you do this on an Air-Gap machine and just transfer the wallet to an online machine.
If not available, just make sure that your PC isn't ridden with malware or viruses.

Lastly, this is getting off-topic so for further Electrum-ltc-related concerns, please create a new topic in 'Electrum' or 'Altcoins' board.

He emphasized that it's because of his current equipment as he may be finding ways to utilize those old laptops.
Probably, purchasing an entire rig with old GPUs isn't an option for him even with that dirt-cheap electricity rate.

In that case, do what I've recommended to contact Ledger and inform them of the situation and the mention the reseller where you purchased it.
Because it's not safe to use that device if it "randomly" generated a seed phrase that's been used by another user.
They might even replace that device since it should still be under warranty.

Users here in the forum wont have the means to help you since they'll need the actual device and specialized equipment to properly debug it.