Are you referring to the same case as in Segmentation fault for OpenLB 1.5 or is it something different?
It would help, if you could post the full code of one failing example as we have not observed any similar problems in 1.5 (both in the examples during release testing and all the work in progress apps for current research). This way we can identify what was missed during adoption of your case to 1.5 and improve the documentation.