Failed to connect. Translation memory file does not exist.

Reason: The TM file does not exist in the first location any more as you have re-located its folder.
Solution: Go to Translation Memory menu > New/Select TM, place the cursor on each TM on the list and click "Edit". Then, click "Browse" and locate the TM file in its new location. Do not forget to click "OK".

Reason: The TM file name includes accented or non-Unicode characters.
Solution: Rename the TM file and locate it again.

Reason: Windows Vista blocked the TM file as it comes from another machine.
Solution: Go to the TM file itself in the folder in which it is saved and right-click the TM file > Properties > and see (at the very end of "General" tab) if it is blocked, click the button "unblock". Then, re-open the client's TM.