I recently installed ImageOnMap on my Paper 1.15.2 server, and when I recently did a backup, I discovered the /maps command didn't show any of the maps I'd created. Some further investigation revealed that there was no data in the plugins/ImageOnMap/maps directory. I've checked, and the directory seems to be set as write-enabled.

The plugins/ImageOnMap/images directory is being populated as I'd expect, and the actual maps we've created and placed persist across restarts.

Do you have any ideas what could be causing this issue? Or do you know where I should look for more information to determine what the problem with my server configuration is?

The plugin seems to have been working fine as far as importing images and placing maps goes. There's just nothing in the maps folder, after we restarted the server presumably it looked for the files, found nothing, and continued as normal. The images folder has content and loads as expected.

I'm using SlothHost - the backup option takes the server down, makes an archive of the entire server folder, then restarts the server once this is complete.

Other plugins I'm using: WorldEdit, VoxelSniper, Multiverse, Multiverse Portals.

The plugin was working before your backup ? Have you copied player's maps file and images folder ?

I updated to 1.16 and the new version of the plugin and this seems to have been resolved. I'm glad it works!