An NPR message indicates that your program is about to read from address zero (read from a NULL pointer). An SEGV signal will result.
One common cause of an NPR error is failure to check return status for a function expected to return a pointer to a string or an object. If the function returns NULL on failure, use of the NULL pointer leads to an NPR error.
Note:
HP-UX can be configured so that NPR messages are not fatal. However, they still represent serious errors. An SEGV happens only if you use the -z compiler option.