Not reading psbt file

[Kaplant4]

My coldcard isn't reading the psbt file on the microsd card.

It did this a month ago, and I then updated electrum to the latest version after which it recognised it and I was able to sign the file on my coldcard.

This time, I don't know what the problem is, as I have the latest version of both electrum and coldcard. Does anybody have experience with this?

[BitMaxz]

What error do you see on the Coldcard screen after you choose "ready to sign"?

Try to make/recreate a new PSBT file again in Electrum put them to SD card but this time make sure to reject safely the SD card reader from the PC.
Now put the SD card to Coldcard and check if it will read the PSBT file.

If not replace your SD card and try again. Also, check the Coldcard firmware version the current latest version is 4.1.1.
Also, try the lower version of Electrum I think 4.1.1 same as the latest firmware version of the Coldcard.

[HCP]

This time, I don't know what the problem is, as I have the latest version of both electrum and coldcard. Does anybody have experience with this?

Did you update either Electrum or the coldcard firmware since you last attempted to send a transaction and/or had the same issue? If so, it's possible that one of them has introduced an issue...

Not sure if you can downgrade the Coldcard... but using an older version of Electrum is relatively easy (you can grab one of the portable versions if you're using Windows and use it temporarily until you resolve the problem). The only issue you may run into is if the Electrum wallet file version has been "upgraded", then a lower version of Electrum will likely refuse to open it... and you'll have to re-import the watching only wallet into Electrum.

[Kaplant4]

Hey,

No, since my last successful transaction last month, nothing changed. So I don't know where the issues lies.

So earlier today j downloaded the older version of electrum 4.1.1, but now it says it's too old of a version to load my wallet as you mentioned. I use a mac so I'm hoping there's a simple workaround.

[Kaplant4]

This time, I don't know what the problem is, as I have the latest version of both electrum and coldcard. Does anybody have experience with this?

Did you update either Electrum or the coldcard firmware since you last attempted to send a transaction and/or had the same issue? If so, it's possible that one of them has introduced an issue...

Not sure if you can downgrade the Coldcard... but using an older version of Electrum is relatively easy (you can grab one of the portable versions if you're using Windows and use it temporarily until you resolve the problem). The only issue you may run into is if the Electrum wallet file version has been "upgraded", then a lower version of Electrum will likely refuse to open it... and you'll have to re-import the watching only wallet into Electrum.

I can't apparently send bitcoin from a watch only wallet? Sorry if I'm being slow, I'm trying to find out what exactly is wrong and hopefully send bitcoin today.

[Kaplant4]

When I go to sign on my coldcard it simply states that it is ready to sign transactions, it doesn't read the files on the microsd card.

[ranochigo]

It works for me, Electrum 4.1.4 and ColdCard 4.1.1.

Is your ColdCard on the correct file format? Assuming that you do not hold anything sensitive on your SD card, you can try formatting it. Do backup anything you want on the SD card first. Afterwhich, go to Advance>MicroSD Card>Format Card. This will remove everything from your SD card and use the correct file system.

[Kaplant4]

It works for me, Electrum 4.1.4 and ColdCard 4.1.1.

Is your ColdCard on the correct file format? Assuming that you do not hold anything sensitive on your SD card, you can try formatting it. Do backup anything you want on the SD card first. Afterwhich, go to Advance>MicroSD Card>Format Card. This will remove everything from your SD card and use the correct file system.

I formatted the card and created a new skeleton wallet as well and still the coldcard doesn't read the psbt file on the microsd card.

Does it have anything to do with the number of inputs and outputs on the transaction window at all? It says 25 inputs and 1 output. Probably irrelevant, but I don't know what else to focus on. Like I said, this happened last month to me, and I simply updated my version of  electrum, after which the coldcard read the psbt file.

Now it seems nothing works. Coldcard version is 4.1.1 and electrum is 4.1.4.

[ranochigo]

Does it have anything to do with the number of inputs and outputs on the transaction window at all? It says 25 inputs and 1 output. Probably irrelevant, but I don't know what else to focus on. Like I said, this happened last month to me, and I simply updated my version of  electrum, after which the coldcard read the psbt file.

Eh, that's actually the issue.

Coldcard supports 20 inputs to be signed at once[1], presumably due to the fact that it is unable to sign so many due to hardware limitations. I've never encountered this issue, only because I've never had to sign that many inputs but I think that the limitation still applies right now. Since it's mainly a hardware limitation, there isn't anything else that you can do other than to split the transaction up smaller.

[1] https://github.com/Coldcard/firmware/blob/master/docs/limitations.md#max-transaction-size

[Kaplant4]

Does it have anything to do with the number of inputs and outputs on the transaction window at all? It says 25 inputs and 1 output. Probably irrelevant, but I don't know what else to focus on. Like I said, this happened last month to me, and I simply updated my version of  electrum, after which the coldcard read the psbt file.

Eh, that's actually the issue.

Coldcard supports 20 inputs to be signed at once[1], presumably due to the fact that it is unable to sign so many due to hardware limitations. I've never encountered this issue, only because I've never had to sign that many inputs but I think that the limitation still applies right now. Since it's mainly a hardware limitation, there isn't anything else that you can do other than to split the transaction up smaller.

[1] https://github.com/Coldcard/firmware/blob/master/docs/limitations.md#max-transaction-size

Thank you. To get the input to 20 or less, I can't send more than 0.02 bitcoin at a time. There surely must be a simple way to change this? I'm not sure what's meant by using a segwir signature and providing only the individual UTXO? Any bitcoin amount that is 0.03 or more is 21 inputs. I've sent more than this a month ago so I'm unsure what's changed.

[ranochigo]

I'm not sure what's meant by using a segwir signature and providing only the individual UTXO?

That is for the PSBT file. PSBT files includes loads of redundant data and stripping it down helps to reduce the size restricted by the communication bridge.

Thank you. To get the input to 20 or less, I can't send more than 0.02 bitcoin at a time. There surely must be a simple way to change this? ​Any bitcoin amount that is 0.03 or more is 21 inputs. I've sent more than this a month ago so I'm unsure what's changed.

Try if it'll sign with <20 inputs first. Use Coin control if needed on Electrum. I think fees are fairly low right now; would it be possible for you to send two transactions back to an address in your wallet (1x 12 inputs, 1x 13 inputs) and spend it with ColdCard, the two created inputs from the two transactions?

[Kaplant4]

I'm not sure what's meant by using a segwir signature and providing only the individual UTXO?

That is for the PSBT file. PSBT files includes loads of redundant data and stripping it down helps to reduce the size restricted by the communication bridge.

Thank you. To get the input to 20 or less, I can't send more than 0.02 bitcoin at a time. There surely must be a simple way to change this? ​Any bitcoin amount that is 0.03 or more is 21 inputs. I've sent more than this a month ago so I'm unsure what's changed.

Try if it'll sign with <20 inputs first. Use Coin control if needed on Electrum. I think fees are fairly low right now; would it be possible for you to send two transactions back to an address in your wallet (1x 12 inputs, 1x 13 inputs) and spend it with ColdCard, the two created inputs from the two transactions?

OK yes the coldcard has recognised the transaction at less than 20 inputs, but it would require 6-8 transactions for me to send the total to where I want to. So am I able to open the psbt and delete certain things to reduce the input?

[ranochigo]

OK yes the coldcard has recognised the transaction at less than 20 inputs, but it would require 6-8 transactions for me to send the total to where I want to. So am I able to open the psbt and delete certain things to reduce the input?

Is there a problem with consolidating the inputs first? Using a few transactions with less than 20 inputs to send back to your own address, and sending the consolidated inputs to your destination.

Deleting the inputs would result in your having less inputs for your transaction, and you need to include them all or else your total amount would be less than you desire.

[Kaplant4]

OK yes the coldcard has recognised the transaction at less than 20 inputs, but it would require 6-8 transactions for me to send the total to where I want to. So am I able to open the psbt and delete certain things to reduce the input?

Is there a problem with consolidating the inputs first? Using a few transactions with less than 20 inputs to send back to your own address, and sending the consolidated inputs to your destination.

Deleting the inputs would result in your having less inputs for your transaction, and you need to include them all or else your total amount would be less than you desire.

To be honest I'm not quite clear on what that practically means.

So do you mean that I open electrum, generate my receive address, then go to the send window and send multiple transactions to my own address? How would sending bitcoin to my own address reduce the inputs.

I know it's probably super simple, just never done it before so I can't visualise and and not sure how consolidating works!

[ranochigo]

To be honest I'm not quite clear on what that practically means.

So do you mean that I open electrum, generate my receive address, then go to the send window and send multiple transactions to my own address? How would sending bitcoin to my own address reduce the inputs.

In Bitcoin, we don't spend funds by looking at the balance on addresses. Instead, we spend inputs and create new ones. Let me show you an example: https://blockchair.com/bitcoin/transaction/c21523ed3745959ce1389f571ec1c46181eb09c10d85301923bf875cfc0fd1b9. The transaction has 3 inputs, by spending them, I've effectively created a single inputto be spent. If I were to replace it with any address that I own, then I would've effectively consolidated it by spending 3 inputs and creating a single one.

If you were to spend 15 inputs in a single transaction to your own address, you'll create a single transaction output for it to be used in the next transaction. The other 10 inputs can then be spent in another transaction to create another inputs. Afterwards, I'll just use the two inputs that I've created through the consolidation into the transaction that I originally wanted to make, but was unable to do so due to the restrictions on the number of inputs.

So, create a transaction that sends back to your own address; Go to View>Tools>Show Coins, then select any inputs, as long as there isn't 20. Go to your Send tab, input an address from your own wallet and press Max. Afterwards, do it as you would for a normal transaction. Upon loading it into ColdCard, you should expect to see a message saying that you're sending it to your own wallet. After both your consolidation transaction gets confirmed, then you can spend it normally, as you've reduced the number of UTXO (unspent transaction outputs) from 25 to 2.

[DireWolfM14]

How would sending bitcoin to my own address reduce the inputs.

Adding to ranochigo's comments; assuming you have 100 current inputs in one or more addresses, and you're limited to 20 UTXOs per transaction, you can turn those 100 UTXOs into 5.

In Electrum make sure you have your addresses tab and your coins tab visible.  On the menu bar select View>Show Addresses, and View>Show Coins.

From the Coins tab you can select one input to spend, or multiple inputs to send together.  From the Addresses tab you select a specific address to spend from, which will select all the inputs to that address.  Also from the Addresses tab you can select an address you want to use to receive the inputs.  You can send the inputs the same address they are coming from, another used address, or select an unused address.

Once you've decided on the inputs to consolidate, send them all to your chosen internal address with the lowest possible fees; 1 satoshi per byte.  Then once all the applicable inputs have been consolidated you can send the consolidated inputs to the recipient.  You don't have to wait for the consolidation transactions to confirm, the default settings in Electrum allow to spend unconfirmed transactions.  If you sent them all to the same address you can select that address from the Addresses tab and send the desired amount to the recipient.  This method is referred to as Child Pays For Parent (CPFP.)  To help pay for all the parent transactions you'll want to use a slightly higher than normal fee for the child transaction.  Make the fee appropriate for your spending needs, then add a few more sats/byte.  This method should help you save a little bit on fees.

[Kaplant4]

You've all been very helpful, much appreciated. I think I've made some progress via the above advice.

I managed to consolidate 5 inputs then send to where I wanted. But a problem I faced was that I originally wanted to consolidate more than 5 (15 or so) but every time I tried, the PSBT file wasn't read by the coldcard until I reduced it to 5 inputs. I've now also tried another consolidation to send more, and this time it didn't even read the 5 inputs but when I reduced it to 3, it's now worked.

[Kaplant4]

Would you know why it works with 3 inputs but not with eight for example? My understanding was that anything less than twenty is fine? The small amount of bitcoin in each input means I would have to consolidate multiple batches of three inputs into one, so I end up with six (consolidating eighteen inputs) or so inputs, which I'd then be able to send as two inputs.

Is there an easier fix im missing?

[ranochigo]

Would you know why it works with 3 inputs but not with eight for example? My understanding was that anything less than twenty is fine? The small amount of bitcoin in each input means I would have to consolidate multiple batches of three inputs into one, so I end up with six (consolidating eighteen inputs) or so inputs, which I'd then be able to send as two inputs.

Is there an easier fix im missing?

Does it violate any of the restrictions in the link? For example the PSBT file size?

[BitMaxz]

I have some solutions for this but I think it will risk your current wallet if you do this in online mode.
This is my solution according to their docs here https://coldcardwallet.com/docs/bip85
You can export a private key(WIF key) if you can export the private keys of your wallet you can import it to Electrum do this in offline mode.
Then after you import the private key get the address(public key) and make a watch-only wallet on another PC/device and make a transaction to consolidate all (UTXO).

This is the only thing that I think will work if the coldcard can't handle many (UTXO).