After updating from Piwik 3.0.4 to 3.1.0 with the "automatic" update, I got the following warning in the diagnostics:
Directories were found in your Piwik but we didn't expect them. --> Please delete these directories to prevent errors. <-- Directory to delete: vendor/szymach/c-pchart/app To delete all these directories at once, you can run this command: rm -Rf /var/www/clients/client1/web3/web/vendor/szymach/c-pchart/app
Probably nothing serious - but it's irritating.
Thanks for the report @arnowelzel
Could you send us the list of all files and directories within this, ie. the output of this command (if you can run commands):
ls -laR vendor/szymach/c-pchart/app/ ?
Sorry, I already cleaned up the path as suggested by the diagnostics (and Piwik works fine so far). I'll try to reproduce the problem with a backup from the point before I applied the update.
See also https://github.com/piwik/piwik/issues/11978 which is the same issue:
The content of the directory is:
app └── cache ├── cache.db └── index.db