If you are syncing on the PC/server end and get the following error:

"The error is: Logon Failed - Exception is:Error in the application"

This error message means that there is something wrong with the ACT! database itself.  For whatever ACT! user you are trying to sync with, we are logging into ACT! with this same user.  The problem could be as simple as an 'ACT! Survey' that has popped up and is blocking access to ACT!.  On the same PC/server where ACT! and Handheld Contact are installed, open ACT! and log into the database as this user. 

Are you able to gain access to ACT!?  Have any of the database path, location, PAD file, Admin access, etc recently changed?

If you are able to get into ACT! as the end user and you dont get any ACT! issues, then you will need to remove the user and re-add in Handheld Contact.

1. Open Handheld Contact on the PC/server.
2. Click on the user that is having issues and choose Tools, Manage, Users and then click Delete.
3. Once the user is removed, click on the 'Add User' button in the upper left corner.
4. Follow the wizard to complete the set up again.
5. When finished, press the 'Sync Now' button on the left to begin the syncing process.

You may need to restart the Handheld Contact Service before you can get it to sync again.  Go HERE for more info.