Look around some other parts where memory may not be allocated to other variables than platzhalter. And check declaration part of platzhalter. It might be re-declated as different type than string, between the classes, blocks, etc. I had similar experiences several times, and sometimes the source of error was not at the exact point the error was raised. Based on my experiences, SIGEGV is trying to access wrong memory place (platz in German? ^^)