Hi Bart,
I couldn't find a problem in here. Maybe it's the dll as suggested by the error message...
Except for your (missing) subvis: Do they do the conversion correctly?
One general hint:
you can wire the error cluster directly to the case structure selector or while loop stop condition!
Best regards,
GerdW

using LV2016/2019/2021 on Win10/11+cRIO, TestStand2016/2019