Help needed Filemanager not showing anything

Hi!
I have a very strange problem with my file-manager - it just stays empty ...

The strange thing is, that it already worked like charm and then suddenly stopped working. Is there a way to figure out the problem? I'm pretty sure that there are no special chararcters in the file-tree...

I'm using Revo 2.1.3 -> updated to 2.1.5 and the problem still exists...
[ed. note: flanger last edited this post 12 years, 5 months ago.]

The problem I had with this was as follows:

Built modx on my Ubuntu laptop.
All working.
Migrated it to a CentOS server
File Manager stopped working
Problem was that PHP installation on laptop had PHP mbstring module, but server did not. This is used by file manager browser.
Ran yum install php-mbstring on server
Restarted apache
Problem fixed

My Hosting Company told me the same thing... Now it's working fine Maybe this should be written in the modx System requirements...