A checklist to be used when a user cannot log on
1. User is allowed log on to CRM via CRM's web services (Allow WebService Access:True)
Navigate to the users details (Administration -> Users -> Users) and view the users details and check that the "Allow WebService Access" setting is set to true
2. MobileX license check.
Navigate to "Administration -> CRM Together -> MobileX " From that screen check that the user is in the list
3. You cannot use the ampersand '&' character or '%' character in a password when using MobileX (this is due to a web-service bug in Sage CRM).
Other strange characters may also be unsupported-remove all to test