App icons in web interface broken

I know this is from several months ago but this same "app icons missing or broken" issue has plagued my 316 for more than a year.

I finally solved the issue.  

It turns out that my apache2 webserver was always booting into "safe" mode.  If you have ssh enabled you can verify by checking the status of apache2 and apache2-safe

systemctl status apache2
systemctl status apache2-safe

In my case, the apache2 status showed "failed", and the reason was because of invalid permissions on the /var/lib/apache2/fastcgi folder.  Specifically the error message was:

FastCgiIpcDir /var/lib/apache2/fastcgi: access for server (uid 98, gid 98) failed: write not allowed by group

The reason is because apache2 is run by user admin, but the fastcgi folder is owned by www-data.

I changed the owner of /var/lib/apache2/fastcgi to admin:admin and now apache2 boots fine.

I'm not sure if this was the "right" thing to do, or whether perhaps apache2 should be set to run as www-data instead of admin or whether fastcgi should be disabled entirely.

One final point:  In "safe" mode, the web interface consistently rebooted anytime I made any settings changes.  I found out that the safe mode was giving this error:

 apache2[24533]: [error] server reached MaxClients setting, consider raising the MaxClients setting

So if your apache2 is indeed not starting correctly and reverting to safe mode, it might be a good idea performance-wise to find the root cause and fix it.