Guru Meditation Error: [...] (LoadProhibited) esp-idf

i am trying to implement .ino file in esp-idf project.

I have only take .ino file that works, renamed in c++ and I repositioned the methods correctly. I've changed something to remove all errors, but now i have this error in while(), when I debug fstFrame->nxt

Guru Meditation Error: Core 0 panic' ed (LoadProhibited). Exception was unhandled

That's the code:

while ( fstFrame->nxt ) {
        printf("\n\nin while cache\n\n");
        frameChunck* f = (frameChunck*) fstFrame->nxt;
        free ( fstFrame->dat );
        free ( fstFrame );
        fstFrame = f;
      }

the declaration are:

frameChunck *fstFrame;  // first frame

and

struct frameChunck {
  uint8_t   cnt;  // served to clients counter. when equal to number of active clients, could be deleted
  uint32_t *nxt;  // next chunck
  uint32_t  fnm;  // frame number
  uint32_t  siz;  // frame size
  uint8_t *dat;  // frame pointer
};