User logon errors when Archive Manager is installed in a non-english language environment (4350568)

Archive Manager is installed in a non-english environment and users might be unable to log on to Archive Manager website or open their mailbox on the Archive Manager website. 

Either error "401 Unauthorized, your session may have been expired, please try to log in again" might appear or user might be unable to see any content of their mailbox. 

Webservice.wlog and / or AMIO.wlog show errors like
HTTP 401: UnauthorizedAccessException - The specified object Id does not exist, or you are not authorized to access it.
(...)
Exception has been caught: System.Runtime.InteropServices.COMException (0x8007052E): The user name or password is incorrect.