It’s unlikely that the theme is to blame. Hubzilla stored the files correctly in `store/pepecyb/` – both the original and the resized versions, with the hash value as the filename – and their paths are correctly referenced in the database within the ‘attach’ table. I’d checked this before deleting them. And it doesn’t matter whether I upload the file via WebDAV or from the web interface. Certain directories cause the error. BTW: These are directories, some of which contain over 200 files… which is why I became suspicious.

I’ve also tried this with Solidified, Redbasic and Adminlte. And whenever I’ve uploaded to one of the rather ‘full’ directories, the file was visible in WebDAV and on the web interface and could also be displayed, but when embedded in a post, the Hub freezes with the error mentioned.