Hi,
This problem has been resolved through Support. Since other users may face the same problem, I will post the results here:
The .tcNM file can be corrupted if its encoding was changed. In Ali's particular case, the target .tcNM file has been saved in the Unicode format when the file has been checked in to CVS, and the file became unreadable for TestComplete. To avoid this kind of problem, please make sure that the encoding stays unchanged.
To be sure that the encoding is OK, check whether the .tcNM file encoding is the same as specified in the file itself. You need to check the following line in the .tcNM file:
<?xml version="1.0" encoding="UTF-8" standalone="no"?>