If Safe Financials was running correctly and then for some reason, nobody could access the system at all then this is likely caused by a change, please contact your IT Team in the first instance.
Below are listed a few of the possible causes:
A change in file and/or folder Permissions for your Users or User Group.
Folders or Files have been moved and/or migrated to a different Location.
Connection to the server.
Permission to connect to the server.
Internet connection.
Memory or CPU maxed on the server.