Electrum - low fee transaction (to Jaxx wallet) disappeared

[sanodimente]

Hello everyone,

I'm very new in Bitcoin system and need some help.

Few days ago i bought some Bitcoin, Ether and Litecoin from Bitpanda. My first purchase ever.
I found out on the web that Electrum is considered one of the best and safest desktop wallet so I installed it.
Plus I installed Jaxx wallet on all my devices (iMac, Windows and iPhone) to have a centralized altcoins wallet accessible also from mobile.

I transferred all my BTC from Bitpanda to Electrum. Everything went smooth and fine. I had them in Electrum in around 15 minutes fully verified.
Same stuff with ETH and LTC to Jaxx. Transactions were confirmed in a matter of minutes.

Then i decided to transfer some of the BTC i had received in Electrum to Jaxx. The amount was 0.015 BTC and i think i made the mistake to set really low fee (the minimum possible, which was 0.00001). It was my first tx from Electrum and i hadn't read much about fee before.
Tx immediately appeared in Jaxx but obviously it was unverified. The strange thing is that after about 20 minutes it disappeared completely from Electrum and the input address showed again the original total amount of BTC i had before the transaction (while it was still unverified in the Electrum history, the amount was correctly diminished of the 0,015 BTC being transferred). On the other side, on Jaxx, the transaction remained there unverified for hours and hours with no changes.

Since yesterday at 4 pm (when i created the tx) till this afternoon the unverified tx was still visible in Jaxx, then i reset the cache and disappeared also from here (both on mobile and desktop version).
Other strange thing is that the tx ID was found (as unverified yet) in some block explorer (like Blockcypher and Tradeblock) but not in others (like Blockchain and Blocktrail). Right now is almost only visible in Tradeblock and not anymore in Blockcypher.

What am i supposed to do right now? The TX has been definitely deleted? i suspect it hasn't... should i try to increase the fee via CPFP tx? How in case since i cannot see the tx in Electrum anymore and seems not to be trackable in major block explorers? those 0,015 BTC will stay in limbo forever?

Thanks in advance... any help will be appreciated

[1715623761]

1715623761

[sanodimente]

Well, it took a while but I solved it out, hopefully... also thanks to this post:

https://bitcointalk.org/index.php?topic=2394204.0

Hope what i find out can help someone:

I've discovered that in Electrum you can load and broadcast again transactions to nodes from ID, file, text and QR code (tools - load transaction).
Unfortunately loading the tx from blockchain just inserting the ID didn't work (i suppose the tx it was out of many mempool so kind of untrackable).

I managed to find the row transaction text on BTC.com (where i could still track the transaction through ID) clicking the link "rawtx" just beside "Size".
I pasted and copied the raw text in (tools - load transaction - from text) and the window of tx details appeared.
I clicked "Broadcast" and the tx was again there in the history, still unconfirmed, but there with the write "Replaceable".

I opened again the tx detail window and added some fee with the slider to have a verification within 25 blocks (0,00035 BTC in total from previous 0,000011).
I signed and finally replaced the previous low fee tx with the new one with higher fee.

After around 1 hour it had 6 verifications and was properly executed.

Just a couple of things:

- on BTC.com tracking the replaced tx i see a warning of "double spent" money... this is normal? It will somehow affect my future transactions?

- when in Electrum console i used the command >>gettransaction("...transactionID...") with the ID of the previous lost tx (before reloading it with the raw text),
Electrum crashed twice. Same command on other verified transaction returned proper results. This is a bug of the software?

[pooya87]

bitcoin is a peer to peer network. this network consists of different computers running an application we call a bitcoin node. when you send a transaction, you are sending it to a bitcoin node. these nodes receive transactions from others and put it in their memory, which we call memory pool or mempool for short. and then they rebroadcast it to others. and that way your transaction propagates throughout the network and usually in matter of seconds.

now here is the thing. each node can decide to accept some transactions and reject some others. for example most nodes set a minimum fee (satoshi/byte) that they are going to reject. so if you send them a transaction that has a low fee they don't accept it.
right now there are more than 170,000 transactions in the mempool. and the size is bigger than 280 MB. so obviously there are many nodes that reject a lot of low fee transactions.

now when you use an SPV wallet like Electrum, you are not a node. you are instead connected to a random node (an Electrum specific node to be exact). and then you send and receive transactions from these nodes.

the reason why your transaction disappeared is that the first time you were connected to a node that accepted your low fee transaction but the next time you ran Electrum, you connected to another node which probably had a higher limit for fee and did not have your transaction in its mempool, that is why when you connected to that node, it told you that you do not have that transaction you were looking for.

that is the same with the block explorers. they also run a full node. some have different settings. for example blockcypher and blockcahin.info reject 0 fee transactions but blockexplorer and smartbit don't. so you see your transaction in one of them and you don't see it in others.

- on BTC.com tracking the replaced tx i see a warning of "double spent" money... this is normal? It will somehow affect my future transactions?

the way RBF works is that you are practically making a new transaction and you are in fact double spending the same output.
this is again because of different Node settings. some of them have implemented RBF so they understand it, and will Replace your transaction By the new one with higher Fee and discard the old one. but some other nodes have not implemented RBF so they only see 2 transactions, they reject the new one because it is a double spend and keep the original.
the block explorers show them as double spend as a warning.

[sanodimente]

Thanks for the explanation man and for the post i linked above... it really helped me to find out what to do.  Really appreciated!

OK, everything is pretty clear. In any case i find quite tricky the fact that Electrum, connecting to a different node, looses the pending transaction. Apart that i didn't close and reopen the software, but the tx simply disappeared during the same session, what i was supposed to do if i couldn't reload the tx from raw text found on BTC.com? Waiting a possibly infinite time for having the tx confirmed, considering that it was propagated only by those few nodes accepting very low fees transactions? Moreover without the chance to track it through Electrum itself... shouldn't the tx at least remain somewhere in Electrum cache and visibile in the UI (eventually flagged with some specific text warning about the pending/unaccepted state), in order to recover the raw text and/or directly re-broadcast the tx assigning a new fee?

However the above mentioned crashes using the command line were quite strange, right?

If i have to transfer BTC from two different wallets of mine, wouldn't be better to import directly the private key in the recipient wallet? Sounds faster, safer and cheaper in terms of fee

Btw I take it as a good lesson that allowed me to better understand some of the mechanisms... next time for sure i'll pay much more attention to the fee i set up

[pooya87]

what i was supposed to do if i couldn't reload the tx from raw text found on BTC.com? Waiting a possibly infinite time for having the tx confirmed, considering that it was propagated only by those few nodes accepting very low fees transactions?

if your translocation is out there, you will find it somewhere.
if it is not out there, and you can not find it then simply spend the funds again. in other words create a new transaction.

and it usually won't be forever. it is either dropped and forgotten, so to speak, or it will be confirmed.

Moreover without the chance to track it through Electrum itself... shouldn't the tx at least remain somewhere in Electrum cache and visibile in the UI (eventually flagged with some specific text warning about the pending/unaccepted state), in order to recover the raw text and/or directly re-broadcast the tx assigning a new fee?

it stays in your Electrum, not in cash but in your wallet file. you can open it in a text editor and see it if you like (although be careful not to change anything!). it is stored there but each time you connect to a new server, your wallet sends that server a request and asks it about transactions that belong to you and the server (the Electrum node) answers back and your wallet updates.

it is actually not a bad thing that not all servers have your transaction. imagine you didn't use RBF and paid a very low fee and now your transaction is stuck. when you have the tx in your wallet Electrum won't allow you to spend it. so you are screwed. but if it is not in your wallet (like when you connected to a new server and it disappeared) you can now create a new transaction with a high (appropriate) fee and resend it and hopefully get it confirmed fast this time.

However the above mentioned crashes using the command line were quite strange, right?

yeah, i have no clue why it crashes, sorry...

If i have to transfer BTC from two different wallets of mine, wouldn't be better to import directly the private key in the recipient wallet? Sounds faster, safer and cheaper in terms of fee

well i can't say if it is better or worse really.
for example if you don't want to move the funds and also if you already have that particular private key backed up, why would you even import it in a new wallet. let it be in your back up.

also it depends on your setup. for example where did this private key come from? is it another wallet? and what is the new wallet you are sending it to? for example if you have the private key from your Multibit and are trying to import it in a new wallet that you created with Electrum, you can not do that because your new wallet contains a set of keys (and new keys that will be created in the future) all of which can be recovered from a seed. but if you import this new one, this key can not be recovered with your seed so electrum does not even allow you to do it.