An NPR message indicates that the program is trying to read from address zero (a NULL pointer) or is indexing off a NULL pointer (Purify labels all reads between location 0 and 0x1000 as NPRs). An access violation subsequently results.
This message can occur when you fail to check a return status for a function expected to return a pointer to a string or an object. If the function returns NULL on failure, subsequent use of the NULL pointer causes a NPR error.
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