open your rpd. go to "manage" -> Variable Manager / New / Session / Variable. so to create a new session variable in the .rpd.
then you create a variable NO_FORCE_TO_DETAIL_BIN and se the default to 1.
BUT....this did actually not do the trick
I have created a logical table that is a table made up of the two that I just want to join and as soon as I create a bi answers report that contain columns from those two tables I see the error 14025.