Options and Document Properties wont save Can't change default dimxpert tolerances

I was designing a part and was trying the lower the DimXpert Tolerances in the Options>Document Properties>Dimxpert>Size Dimension. And when I click "OK" I then decide to go back to the document properties to see if they are changed and they are NOT! I even try and run dimxpert auto dimension but still its just the default tolerances and no matter how many times I go back into document properties to change them, click ok - nothing; they cant be changed?

I tested other things in Options, default template (system options) doesn't get saved when I click ok, wording fonts (document properties) do however.

I need to analyses a tolerance stackup and I dont want to re-tolerance every little dimension, the default of 0.5mm is massive! 

It doesn't make any sense and I've spent a day trying to understand whats going on so if anyone could know what to do it would be great.

Thanks,

Kind regards,
Sam

SolidworksParts And Features