Dear David N. Jansen, Thanks for your answer dated May 2, 2013. I apologize for the delay in responding but after submitting the bug, I did not receive any answer in my mailbox. I now understand that the answer was posted to the MRMC mailing list, to which I did not register, so I only saw your anwser today by chance browsing the mailing-list. Indeed, I agree that the .tra file was not a correct input file for MRMC, because it was in PRISM format, which is similar yet slightly different. The point of my bug report was different: given a wrong input file, MRMC should emit an error message, instead of crashing with a memory problem *** mrmc: double free or corruption (!prev): 0x09e3b008 *** This was really the essence of my bug report. All the best Hubert -- ',',',',',',',',',',' Hubert GARAVEL | Inria - LIG / CONVECS ',',',',',',',',',',' hubert.garavel@inria.fr | 655, avenue de l'Europe ',',',',',',',',',',' tel: +(33) 4 76 61 52 24 | 38330 Montbonnot St Martin ',',',',',',',',',',' fax: +(33) 4 76 61 52 52 | France ',',',',',',',',',',' http://convecs.inria.fr/people/Hubert.Garavel