quartus compile error Case choice must be a locally static expression

Hi,

i compile a code in quartus that has case-when statements nested in a for loop and each value checked depends on the loop variable.

Quartus complains on this with the error 'Case choice must be a locally static expression'.

Is there any workaround for this problem? it would be manually hard to unroll the loops.

I tried to change vhdl version to 2008 but did not help. I also saw some discussion on setting a parameter --relax <someting>...

For the record, this case-when statements did not produce an error when compiling on Sinplify

Thanks