The API functions probe the buffers passed to them and scan string parameters in an attempt to ensure that the data is accessible. These probes can cause faults if the pointers are incorrect (for example, if they are pointing beyond the end of a segment or outside a permitted memory region).

If you get a fault within a LAN Server dynamic link library, attempt to trace the code through the call. By noting the values that are being tested, you usually can recognize the parameter that is causing the problem. Also, check buffer sizes carefully, because the API functions probe the first and last byte of a buffer even if the data returned or received does not fill the buffer.

If you get a stack overflow, extend the stack size. There is no absolute rule for determining the depth of a stack that a LAN Server API function requires. Generally, allow 4KB of free stack space for each function call.