Unconfirmed transaction after 4 days; getting worried

Hey community! I’ve read a bunch of other threads on similar topics and it looks like everyone’s transaction has gotten confirmed eventually.

Transaction ID is 95f9c08d744e78f079130ca70ac2844926ce0c3bdd85790f36db18fed92caccc . I have tested sending smaller transactions afterwords and they all went through within minutes.

I read an interesting thread from October where a knowledgeable member spoke about a bug about too many transparent inputs being an issue for mining pools to mine. My transaction has 388 inputs, 2 outputs, which is less than the transaction in the thread I read. The index on zchain shows as -1 which I’ve never seen before.

Anyway my question is multi-part: Will this transaction eventually go through? what’s the longest I can expect my transaction to remain in unconirmed limbo? Is there anyway at this point to cancel the transaction (sent to Bittrex) and redo it? Will the coin sfhow back up in my wallet at some point. Any help would be appreciated.

It should get mined eventually. Background. Some mining pools use a configuration option to limit the number of inputs they are willing to mine e.g. Flypool is around 150 but some others accept 500. The reason for this is that as the number of inputs rises, so does the time to prepare a block for mining, which might impact their chances of winning the race to mine a block. This “quadratic hashing” issue has been resolved in the upcoming network upgrade, Overwinter, scheduled for June/July. At that point the configuration option will be deprecated and mining pools will stop using it so transactions with hundreds of inputs will be mined promptly.


Did you try an accelerator site?

no, I read about accelerator sites, but I could not find one for zcash. Can you direct me to one?

thank you for the explanation. Makes sense… too bad I cannot mitigate this in advance since when I try to transfer money, I have no idea how many inputs will be used. I guess all I can do until the network upgrade is move coin around in smaller amounts.

When you say eventually…do you mean days, weeks, months?

thank you

Would the new experimental feature of z_mergetoaddress be useful in this regard? See the section on UTXO merging here https://blog.z.cash/new-release-1-0-15/.

Edited to add, it’s not going to help your stuck transaction but for future ones.

Well…it’s been 9 days now…0 confirmations. Can anyone tell me how long I may expect to wait for a transaction with 388 inputs and 2 outputs? Right now I am completely stuck in limbo and seem to have absolutely no recourse. This is problematic for anyone trying to move around zec and relying on someone mining my block in a reasonable amount of time, without knowing in advance how long it will take.


we’re in the same hole here, and i’m trying this Cancel unconfirmed transaction , syncing at 30% here…

Do the imports by “IMPORT ONE PRIVATE KEY” it might by the only way to force the wallet software rescanning the blockchain !

I am trying this process. Just started syncing the chain on my new winzec instance. Will report back, probably tomorrow sometime when it’s all done

worked ! (20 characters)

are you sure? I followed the process and while the coin showed back up in my wallet and unconfirmed transactions in my wallet history were removed, the old transaction still shows on zchain as unconfirmed, and I tried sending out a small transaction from the coin that returned to my wallet and it’s not being sent up to the chain to be confirmed… so while I see the 4.2 zec back in my local wallet, I can’t do anything with it.

Hello, there can be multiple reasons why your transactions has not been mined. For further information, check out this entry in our FAQ: https://z.cash/support/faq.html#transaction-not-mined

Right now, there are no great ways to “cancel” a transaction–we’re sorry about that, and we know it’s a problem. We’re working on it–after the Overwinter network upgrade (June 2018; https://z.cash/upgrade/overwinter.html), all transactions expire after ~10 minutes/20 blocks, so that you can try your transaction again with some modifications.