PHP errors (libpng)

[janipewter]

Actual behaviour

Nextcloud logs show loads of these errors:

imagecreatefrompng(): gd-png: fatal libpng error: invalid block type at /var/www/nextcloud/lib/private/legacy/image.php#582

Expected behaviour

Not this error

Steps to reproduce

1. Upload png files
2. ???
3. Profit

Environment data

Ubuntu 16.04 ESXi virtual machine
Nextcloud server version: 13.0

Logs

Web server error log

Nothing interesting

Nextcloud log (data/nextcloud.log)

See top of post

NOTE: Be super sure to remove sensitive data like passwords, note that everybody can look here! You can use the Issue Template application to prefill some of the required information: https://apps.nextcloud.com/apps/issuetemplate

[MorrisJobke]

Could you provide us one of these PNGs?

[janipewter]

I don't know which PNGs it is failing on. All of the PNG files in my NC server are screenshots from my Android phone and they all seem to have working thumbnails. How do I clear the log?

[MorrisJobke]

How do I clear the log?

Open the file and remove the files you want to have cleared. Or remove/rename the whole file. (Default location is nextcloud.log in your data dir)

[blizzz]

any update?

[MorrisJobke]

As there is no feedback since a while I will close this ticket. If this is still happening please feel free to reopen.