Gosh – what version of SP did you upgrade from?
You need to check the new location of the custom icons folder. By default it will be in the /wp-content/sp-resources/folder – and then edit the location on the panel.

I have the same problem as Franco. I upgraded from 4.4.5 which is supposed to be okay. I deactivated 4.4.5, moved the directory into a backup location (outside of plugins) and then unzipped the beta.

Everything else seems to be okay. My forum isn’t yet active, so it isn’t particularly urgent for me.

I tried creating the structure styles/icons/default/custom, and even gave each of the directories wide open permissions, but I still get the error.

Finally, I clued in that it’s still looking in the simple-forum rather than simple-press. I changed that and it is okay with the location now. Even with the permissions set back to 0755.

However, I suspect that this isn’t the proper place, so I’d like to put this back into the sp-resources folder. However, after looking at the sp-resources folder I can’t see where the icons should be. I have 7 subfolders there:

forum-avatar-pool

forum-avatar

forum-badges

forum-language

forum-plugins

forum-policies

forum-themes

There are also 4 subdirectories left in wp-content from the old version: the upload directories for files, images and media as well as the smileys. They are all empty except for smileys. Is there a way I can migrate them into sp-resources?

yes, in 5.0, the base plugin directory changed from simple-forum to simple-press…

are you using custom icons?  if not, you can just ignore…

but the folder can be whatever you want…  I would just recommend creating a new directory under sp-resources called forum-icons…  put them in there if any, and change the storage location…