Hello guys I have an issue that I can seem to resolve. When I process my picture using weighted batch pre-processing I'm getting large white gradients around the edges of my master light. The issue started when I switched to the Optolong L-Pro Filter filter for galaxy season. I have retaken all my bias, flats and dark's with the new filter. My equipment I'm imaging with is the ZWO ASI294MC Pro With a Hyperstar V4 on a C8 scope. I shoot all my shots at -10c, gain 120 and offset zero. My exposure times are five minutes. My target value I'm using for my flats is 25k ADU. I take my bias and dark's both at -10c. I use Sequence generator Pro to capture all my pictures and calibration files. I get this error message when I run batch pre- processing. **Warning: Only master bias will be used to calibrate flat frames (filter = noFilter, Binning = 1, exposure = 0.01s, Length =8) I have tried everything I can think of. Any ideas on what I can do different?