The problem seems to be that the UTXO simply isn't available anymore in core, because the transaction is already sitting in your own mempool.
Due to the missing internet connection, however, it didn't get broadcasted and therefore no other node is aware of this transaction.

You can either publish the raw transaction by yourself, as mentioned by BitMaxz or you can start core with the argument -zapwallettxes.

Did you solve your problem?

If not, you might want to check whether electrum had a connection.
If you imported your private keys and have chosen the correct address type the issue might just have been that there was no connection to an electrum server.

Can you confirm that the addresses containing the BTC in armory and the addresses from the imported private keys in electrum started with the same char (1.. 3.. or bc1..)?

Mit Vermeidung der Blockchain Analyse ist natürlich gemeint, dass jemand der keinen Zugriff auf dein Gerät hat, versucht verschiedene UTXO / Adressen in Verbindung zu kriegen.
Das Adversary Model sieht quasi vor, dass jemand der Zugriff auf deinen Rechner hat, nicht darauf aus ist deine Historie zu sehen, sondern deine Coins stehlen möchte (was ja prinzipiell auch Sinn macht).

Wenn dein Gerät kompromittiert ist, ist die Privatsphäre dein geringstes Problem.




Naja, die Frage ist in erster Linie ja, warum du deine Historie/dein Wallet auf deinem Gerät so verbergen möchstest, dass niemand darauf zugreifen kann.
Prinzipiell sind deine Coins in Gefahr, wenn du nicht sicher sein kannst, dass deine Hardware und dein Betriebssystem integer sind. Da stellt (wie auch schon oben erwähnt) die Privatsphäre kein großes Problem mehr dar.

Eine Festplattenverschlüsselung ist hierbei der einzig wirklich sinnvolle Weg.

Das nur mal vorneweg 


So wie ich das bei dir jetzt heraus gelesen habe, wäre es vermutlich am besten wenn du in der Tat die gesamte Wasabi Installation in einen Container steckst.
Aber generell stellt sich halt wirklich die Frage, was dein Thread model ist. Also quasi wogegen du dich schützen möchtest. Wenn du das genauer beschreibst, können wir dir vermutlich noch bessere Lösungsvorschläge liefern.

Let me correct that for you:
Dear OP, if you don't want to update macos, you should really realy reconsider storing private keys (or any other sensitive data) on your computer.
You are using an outdated OS which does not receive necessary security updates anymore. It is like an open barn door for anyone interested in entering your computer.

Your options seem to be:
1) Recover the text file.
2) Remember your password.

If you did only store the mnmeonic code inside of a text file, you can not recreate your wallet.
Do you really not remember the password you just set for the file? Did you choose a pretty random one and saved it in the same text file?

You should definitely make a backup of your wallet file. Because if you lose that, recovering the password won't help you anymore. Is there any chance for you to recover your password?

Stories like these are one of the many reasons we always recommend to write the words down on a piece of paper instead of saving them digitally.

Check the history tab of electrum. When did the transaction emptying your wallet take place?
What did you do that day? Did you download some new software?

Also, can you confirm whether you have checked the signature of electrum before installing it?

Is your wallet password-protected? Did you open it the day the transaction was sent?

How did you store your backup (mnemonic code)? Only on a piece of paper, on your PC, online?

Zu 1)
Du hast recht. Das geht so nicht.
Der Grund liegt darin, dass wenn jemand physischen Zugriff auf deinen Rechner hat, derjenige an deine private keys möchte und nicht nur die Transaktionsliste sehen will. Das ist das adversary model von wasabi.
Das Ziel liegt darin, Blockchain Analysen etc. zu verhindern.


2)
Das ist so beabsichtigt.
Wirklich gebraucht wird das Feld ja tatsächlich wenn du eine Transaktion sendest um zu wissen welche UTXO's du zusammen verwenden darfst und welche nicht.
Die Entwickler wollten das Menü relativ schlicht halten.. Ich fände es aber auch besser wenn es im "History" Tab zu sehen wäre.

Das die Adresse aus dem "Receive" tab verschwindet, ist absolut normal und auch so erwünscht.


3)
Wasabi sollte sich (wenn nicht in den Optionen deaktiviert) nie ohne Tor verbinden.
Solante unten "Tor not running" steht sollte auch "Backend not connected" dort stehen.

Das Wallet kann ja ruhig schonmal geladen werden (von der Platte in den Hauptspeicher). Aktualisiert werden die Transaktionen / das Guthaben aber erst wenn dann auch das Backend verbunden ist (was dann eben nur mit Tor gemacht werden sollte).



Wenn ich was übersehen habe oder du noch weitere Fragen hast, immer her damit 

Would you carry all the money (which you got in BTC on your mobile) with you in cash in your wallet?
If yes, then go for it. If not, then don't do it with BTC on a mobile wallet.

As TryNinja already mentioned, mobiles are usually more secure than windows computer.
But still, one shouldn't store large amounts of BTC on an network-connected device (regardless whether it is ios, android, linux or windows).

A VPN does not increase the security at all.
The whole purpose of a VPN is to circumvent geo restrictions and similair.

Regarding privacy.. you are shifting the trust from your ISP to the company providing you the VPN service. Please note that these companies make money with your data. Even if they claim not to.

There are multiple attacks which do double-spend a transaction with 1 confirmation.
Most of them either require a collusion with a miner or to sacrifice a block reward.

While it is technically possible, it is highly unlikely, not guaranteed to work out and too costly to perform.




Always at least 1 confirmation.
If the amount is extremely high (in your opinion), wait for 3-6 confirmations.

This statement itself is not completely correct.
A single seed allows you to generate an almost infinite number of private-/public key pairs (and therefore addresses). A "wallet" basically is just an interface and/or a piece of software/hardware managing private-/public keys.

Further, there are more ways to link addresses without them being used in the same transaction, than just knowing the seed.
For example by knowing the master public key or the master public key or (under given circumstances) by meta data analysis.

No.
There is no link visible between single addresses generated from the same seed.

As long as you are not signing a transaction with inputs from both addresses, or are being analyzed through some meta data (e.g. using web wallet from browser X with addons y,z and a specific resolution, etc..), you are fine.




No.

Just a small remark.. while most lightweight clients do heavily invade the users privacy (including electrum), there are still lightweight clients available which do preserve the privacy.

The most recommendable would be wasabi. But samourai (as a mobile wallet) is a pretty good candidate too.

If OP is looking for a wallet which has a simple backup mechanism in form of a mnemonic code while also not giving up on privacy, wasabi would be my #1 wallet.

That basically is a RBF. That's how one would implement a RBF with core and the appropriate flag being set.



Actually, they don't.
That's the whole point of bitcoin. If it would require trust, it would have failed on what it was meant to achieve. A trustless, decentralized and uncensorable payment network/protocol.

Wrong usage can - under given circumstances - require trust.

I don't see a single reason to recommend "trust wallet".

It is just another random closed source wallet with no specific features other wallets don't have.
And the fact that it is being hyped that much by relatively new (or low level) accounts just makes me more suspicious.

Definitely wouldn't specifically recommend it.




Probably just paid shills.

Kind of, yes.
I don't know enough about blockchain.com to answer that question with 100% certainty, since i didn't use at any time.

But the 12 words definitely were not a backup of the seed back then. So, basically, yes. Just another way of password.



I am not sure what you exactly mean with QR codes
Blockchain.com (formerly known as blockchain.org) was created roughly 9 years ago. And they definitely didn't follow BIP39 back then.

I wouldn't recommend exodus to anyone. Exodus has its own vulnerabilities (or rather: a weak security concept overall).

Just because a wallet is non-custodial, it doesn't mean it is reliable or secure.
You can never be sure whether the software you are using is secure or even malicious. Nothing keeps the developer to give you a mnemonic from a pre-defined list or just using a weak RNG (either by accident or maliciously).

Using closed-source software to store a form of digital decentralized and uncensorable money is a contradiction in itself.

I am kind of shocked that no one even mentioned the implications in terms of security..
You shouldn't trust any device to be secure. The person in control over the hardware, is in control over the whole system. And this includes any data/information passing this device.

In fact, you should always assume that a device not owned by you is compromised. Either by the owner himself or without his knowledge.
Would you really trust your private data (private keys, logins, ..) someone who you don't know how he/she handles security?

Publishing the public key is not a problem. It is called public key for a reason.
Once you have made a transaction from an address, your public key gets publicly known anyway. It's neither an security nor an privacy issue.

Only the master public key can pose some security and privacy risks when exposed.



As the name says, a private key should always stay private.



Not necessarily. There are situations where you kind of need to share your email address.
Using multiple addresses for different things is recommended.

Receiving phishing mails itself is not the problem. Falling for them is. Being cautious is the key here.



There is a difference between privacy (giving away personal information / keeping it private) and security (protection against theft / malicious adversaries).

There are multiple ways to circumvent that.
You could either only allow 0-conf transactions if they are send without the RBF flag which makes it much harder (not impossible) to double spend a transaction. That's definitely fine for low value (coffee) transactions.
Another option would be to use a 2nd layer (e.g. lightning network). And the 3rd option would be to simply accept the risk. I mean.. it's just a coffee. Who is gonna steal a coffee. And even if there is someone who does exactly that, you might have some cameras to prohibit him entering the building again.
Losing one out of a few hundred coffees to a double spend isn't too much and definitely manageable.