fatal signal (ACCESS_VIOLATION)

manu

I've written a quite complex (interpreted) UDF for transient boundary conditions that can be compiled without error message. But as soon as I activate it in Fluent, I get this error message:

FLUENT received fatal signal (ACCESS_VIOLATION) 1. Note exact events leading to error. 2. Save case/data under new name. 3. Exit program and restart to continue. 4. Report error to your distributor. Error Object: ()

If I activate it with a test case file (a simple straight tube), it seems to be accepted but as soon as I use a dat file or when I initialize the solution, I get the error message mentioned above. Does anybody know what to do?