Hello. First reboot your machine and see if the behavior persists. IF it does I would move the TSF.data file. It will resemble this: ADSKFLEX_NUMBERS_TSF.data. It should be located here:
Documents and Settings\All Users\Application Data\FLEXnet
Find this file and change the extension to something different, like ADSKFLEX_NUMBERS_TSF.data.BAK or completely move it from this folder. We don’t want to destroy it, just get it out of the way.
After it is moved or renamed, start the program. A new TSF DATA file will be created and possibly a log file. If the program now works, great, if not, delete the NEW TSF.DATA file and the log and place the original file back in this location, or rename back to ADSKFLEX_NUMBERS_TSF.data
Now try to start the program. If you are asked to register, do so and you should be set.
If this does not help I would probably uninstall and reinstall the program.