We have managed to reproduce the issue in our labs. However, at least in our case, the application crashes with this exception code even if it is called outside CodeXL.
It seems like the AMD driver has an issue where if you request a NPoT number of samples, the call to glTexImage2DMultisample causes a crash (instead of simply "rounding" up to the next allowed number of samples, as the spec says). I have notified the OpenGL driver team of this issue.
In the meantime, you can just place the correct value (1, 2, 4, or 8 - seeing as your code says it needs 6 samples, I'd guess 8 would be the correct choice) in the function call, to avoid the crash.
Hope this helps,