Hello,
There was a bug to continue a computation from a restart file for the 1st tracer stored in the PREVIOUS COMPUTATION FILE, but it was solved in the latest release v8p2r0, but also v8p1r2 (but not before). Which release are you using? If not using the latest release, I strongly recommend you to use it if you want to use the fix.
Anyway, if you do not have any tracer in your PREVIOUS COMPUTATION FILE, that means that you did not write it correctly in your previous run, it is not a TELEMAC issue. If you visualise the PREVIOUS COMPUTATION FILE, can you see a tracer concentration or not? Or if using the python command:
run_selafin.py scan name_of_file, what name of variables can you read (top of the listing)?
For the keyword VARIABLES FOR GRAPHIC PRINTOUTS, you have to write T1, T2... T9, or T* to get every tracer from 1 to 9, or T1* to get every tracer from 10 to 19 e.g. as written in the dictionary telemac2d.dico or the TELEMAC-2D reference manual.
Hope this helps,
Chi-Tuan