Exporting Image files (intermittently) doesn't work:
I get messages back indicating the error is to do with escaping characters:
Syntax::stresc: Unknown string escape \\U.
I am answering my own question to help out other .Net/Mathematica developers in the future.
I am using random file names (DTWERG, ERYFGJ, IYIGGD) and it turns out when Mathematica exports an image file that has a slash and followed by : b, t, n, f, r it recognises/honors the escape slash.
For example when a file name starts with an r as per the screenshots, it treats the
Using forward slashes rather than backslashes resolved the problem: