Hi Freckl,
I’m sorry but this is up to developers, they know about the problem and they will fix it eventually, is not good practice to use beta builds for commercial works for this very reason.
The product was created and tested with V5(which is still the official commercial version), even if we support only V5 it was working fine also with older V6 builds until very recently and as far as I know is still working, there are just a very few shaders creating issues(if this is not the case and you have issue with all the shaders let me know since you may have a different problem).
Please do understand that is really up to developers to provide compatibility between versions, V5 is still the current version and we sell the product for V5 only even though it should work also with V6(the bedroom posted on the previous page was created with V6 for example).
All I can do is sollecitate developers to look in to the issues.