The resource file is not valid. Overwrite it with a new empty one dialougue is when the program aims to open a FOXUSER.DBF and FPT file in the root application directory

If this happens it is either corrupt files or (more likely) an access rights issue.

The first thing to check is whether it's a rights issue or not (this example will be focused on the IT department to follow), to do this, ensure the user(s) who launches the P11D Organiser has read, write and execute permissions recursively from the /P11D/ directory onwards. 

In the most likely case, the P11D Organiser will be located on a server, and the user access this from a shortcut on there desktop pointing to a UNC path, i.e.; \\server\share\P11D

The user will either be a standalone user, or more than likely in a group within active directory. Ensure they have full access, for instance:

You will then either need the user(s) to reboot the machine, or force a group policy update, for instance:

If this does not resolve the issue, it is likely a corruption problem and you will need to contact a member of our support team.