How to set up all local disks in initial backup?

Noob question mby, but i’ve spent a lot of time and still had no answer. Help needed.

For now i need to backup only specific files, for examle *.doc. The problem is that all the PCs in the office have different number of disks (C+D or C only or C+E+H).
So if i leave “Default directories to backup” blank on the server then i receive error “No paths to backup configured”, if i enter “C;D” and PC have only 1 local disk C:, then the error is "Cannot get volume for path “D:”. If i enter “ALL” like it is recommended for image backup, then the error is “Error getting complete file “TjhuYTJvQCbrCFoNaWBI|ALL/Documents and Settings” from ***. Errorcode: BASE_DIR_LOST (7)”

How should i configure the server?
TY

Found this in related topic:

The ALL parameter only works for the image backups and not for file backups. I’ll consider adding it for file backups as well. Meanwhile there is a hidden feature to not stop on index errors of a directory.
You have to give the backup folder a name and append /optional . That is for example
C:\|C/optional;D:\|D/optional;E:\|E/optional.

Will try it.

With the newest beta in https://forums.urbackup.org/c/testing , the ALL also works with file backups