Error during local Motion Correction - object of type 'NoneType' has no len()

Welcome to the forum @LeoTR.

Do I understand correctly that between two otherwise identical jobs, the change of a single parameter determines success or failure?
Please can you post Extraction box size and Fourier crop to box size for for a pair of failed and successful jobs. If the critical parameter is a different one, please post those values also.

Please help future visitors of this forum finding relevant topics by posting the text of Tracebacks and error messages.