Photo corrupts document with live stack group on save

[Maxdanger]

Hi Affinity team,

I was working on a landscape astrophotography document and used the live stack feature to stack my foreground for noise reduction. This was all working perfectly and I even added a mask to remove the stars and a merge visible layer on top. Until the point, Photo was running flawlessly. But when I saved, I got the following error message and now the file is corrupted:

I've managed to isolate the issue to closing the lid/locking the screen. If you have Photo open and haven't locked the computer, it will save no problem, but if you close the lid (like I did on this document) before saving then it will corrupt the document. I've recorded a video showing the bug here:

Perhaps related to this, I notice that when I go to load my source images after locking my laptop (1:28 into the above video), the file path is different. Usually it remembers the last used path even when you quit the application. Thought it worth flagging in case they are connected issues.

I'm using:

2021 M1 Macbook Pro 14 inch
MacOS 14.0 Sonoma
Photo 2.2 (build 2005)
I am saving to an external drive (Sandisk extreme pro SSD)

I've seen posts on the forum where Affinity is able to help recover corrupted documents, would it be possible to ask you to try to recover my document? The file is too large for me to upload (1.5gb), so would you be able to send me a link so I can upload the file to you?

Thanks very much in advance!

Max

[NathanC]

Hi @Maxdanger,

We've not been able to replicate this on Sonoma using an external drive as of yet, following your recording exactly always allows the live stack to be saved correctly the second time round. The main difference is that i'm trying to replicate this on an iMac pro instead a Macbook so I can only lock the screen rather than close the lid so i'll se if I can get a similar macbook model to compare. I've also got a few follow up queries/requests below:

• Can you replicate this with your .TIF files on the local disk and saving locally to take the external drive out of consideration?
• In the recording you Quit the app in between locking the screen and creating the stack again, is this a requirement for the corruption to trigger?
• Could you possibly provide me with a copy of the .TIF files used in your recording? (Dropbox link below)

https://www.dropbox.com/request/rAy60khLNdWgBUCLE9io

Feel free to upload your corrupted document to the same link above and we can see if it can be recovered by any standard means, and failing that it can be logged with the developers for further investigation. There's no guarantee that the file can be recovered as this is primarily for investigation into what caused the corruption so it would be best to revert to a backup if possible.

Many thanks

[Maxdanger]

Hi @NathanC

I don't have an iMac so sadly I can't test on the same device as you, but what I would say is that I get the bug when I hit the lock button as well as when I close the lid, so I'm not sure it would matter testing on a laptop vs desktop given the trigger isn't closing the lid but the locking of the computer. To your first point, I'm guessing this is more to do with the drive I am saving to:

1. I can't replicate this when the Tifs are stored on my hard drive so this does appear isolated to the external SSD. In case you had one around to test with, I'm using this SanDisk drive - https://www.amazon.co.uk/gp/product/B08GV4YYV7/
2. Quitting is not necessary to trigger the bug, simply closing the existing document and running another live stack is sufficient - let me know if you need another screen record. Also if you need me to provide logs of the bug in action I'm happy to provide (if you could explain how to capture said logs )
3. Yup of course, I've uploaded.

Don't worry about trying to recover the document. I don't have a backup as the first time I tried to save was when the corruption occurred. I ended up starting from fresh and made sure not to lock the computer until it was saved and closed.

Thanks very much
Max

[NathanC]

Hi @Maxdanger,

Thanks for following up and providing the sample files, I've since been able to get a M1 Macbook on 14.0 and attempt to replicate this but unfortunately whichever way I try (lock screen/close the lid) the second time round continues to save as expected using your TIF files, the only way I can get it to fail is to unplug the drive during the save, which prompts the file access loss error as expected.

Evidently the cause of the problem is the external drive if this works as expected on your local drive. The external drive i'm attempting to replicate this on is a little dated compared to what you're using, so i'll try a few different ones. Could you possibly confirm what format your Sandisk drive is using? You can check this by right clicking the external drive in finder > Get info and it's format type should be listed here.

Thanks again

[Maxdanger]

Hi @NathanC

No problem - thank you very much for spending the time to investigate. Here's the information about the drive, I'm at work right now but I can try to test on other drives when I finish to see if I get the same behaviour:

 

Thanks very much
Max

[Maxdanger]

Sorry for the delay - my other portable SSD has decided to fail so I can't test on any further drives (sorry about that!). Do let me know if you need me to provide any further info on this.

Cheers

[NathanC]

Hi @Maxdanger,

That's no problem, I'll follow this up on Monday when I can get my hands on an  external NVMe SSD and let you know.

[NathanC]

Hi @Maxdanger,

Just a quick update on the above, I've now tried to replicate this with a 250GB External SSD formatted as ExFAT but the results have been the same with this always working as expected unfortunately (be it close the lid/lock the screen, quitting/not quitting between locking the screen), I've got one other potentially similar SSD to yours to try so i'll see if I have any better luck with that.

[Maxdanger]

Thanks for the update! As always, really appreciate the effort you guys put into investigating our bug reports

[NathanC]

Hi Max,

Unfortunately the problem can't be replicated on the NVMe SSD I've got either after attempting this a few different ways, If you were able to test this on an alternative external drive for comparison that would be great as it just helps confirm if there's something app/environment related but if that's not possible then no worries.

Evidently since the problem only occurs on the second round of saving it would be best to load files stored locally to avoid the problem going forward.

[Maxdanger]

Hi @NathanC

Good (and bad) news. Good news is I managed to sort my other SSD and so I was able to test this bug with it. Bad news is that I got the exact same error where it corrupts the file on save. It's a slightly different SSD and here's the info:

 

This is the link to the one I bought https://www.amazon.co.uk/SanDisk-Extreme-Portable-SSD-Read/dp/B078T9SZ3K/

Happy to record another video demonstrating it on this external drive too

Many thanks
Max