Anyone else having problems with materials not processing? We have Mv BSB 25 and 26 installed on our PCs and this problem affects all of us!

We can process most materials with Mv BSB26 but we have one material that will not process on our beam saw. Mv creates the .xml file. If we process this one material with BSB25 all is good! we've tried deleting the material and recreating it but still not processing through BSB26.

Anyone got any ideas? had the same issue?  what was the 'fix'? we'd like nothing better than moving over to BSB26 but as it stands we have to keep BSB25 to get round this issue.