What would cause matOpen in libmat.dll to return null?

I am working directly with MATLAB's libmat.dll in a LabView application to build .MAT files.

I am finding the matOpen function call occasionally fails and returns null, what could be causing this?

Answer 1

[MathWorks Support Team]

The following events can cause matOpen to return null:

General File error (Permissions, corrupted)

Failure to Identify the version of the MAT file

Invalid open mode