You don't say what version of Amicus or Timeslips. If Small firm and doing this on server make sure you can open Timeslios on server. If Premium the same but try the link with Timeslips closed.
Did anything change recently? Service release installed ? Anti virus updated?
Can you provide exact error?

I am using Timeslips 2015 and Amicus Premium 2012. I have always had to close Timeslips to do the exchange but have tried it with both open and closed. I continue to try to think of things that may have changed in the last month to try to pinpoint the cause. I have uninstalled all programs that I thought may have caused the problem.
Amicus does not give an error code or anything, the error simply states "The file could not be exchanged successfully with Timeslips". I am certain that the link is working because I can post time with no problem, it is only exchanging new files.

What version of Amicus and Timeslips? If Amicus small firm make sure Timeslips can be opened on server. If Amicus Premium try with Timeslips closed.
Did anything change on computer - service release installed, anti virus update?

As mentioned, I am using Timeslips 2015 and Amicus Premium 2012. I have always had to close Timeslips to do the exchange but have tried it with both open and closed. I continue to try to think of things that may have changed in the last month to try to pinpoint the cause. I have uninstalled all programs that I thought may have caused the problem.
Amicus does not give an error code or anything, the error simply states "The file could not be exchanged successfully with Timeslips". I am certain that the link is working because I can post time with no problem, it is only exchanging new files.

I have now tried uninstalling and reinstalling both Amicus and Timeslips and the problem persists. Can post time, but not exchange files

Can you successfully open Timeslips on the workstation? Can you go to the server and go through the link setup?

Thank you for your ideas on this. I think that I have figured it out. Some items were moved around on the server to make room for backups and the problem began right about then. I am hoping to confirm that on Monday with my IT guy. Thanks again