Thanks a lot.
The MemLimit had already been set to 0 (as you gave the hint https://coderunner.org.nz/mod/forum/discuss.php?d=386).
I will try to increase the numsprocs to 200.
I hope that solves the problem.
PS: As I want to use the same thing also for C (I probably will copy the protype at the end to have a fix unique ace-language) setting the MemLimit to 0 is probably more dangerous for C, is not it?