Jeroen knows more about this.

In the new compositor the Max Blur setting is a required field and must not be set to zero. Please increase this to 16 or 32 or something and test again.

Could you retest?

when loading old files we should set the setting to something useful. Not sure, thought it was in place.

Yes, it works fine, now. Thank you.

Although sometimes I get the first row not blurred if the size of the chunk and the max-blur value are i.e 32x32 and 8.000.
But if I change the chunk-size (i.e. to 256x256) or the max-blur value (to 7.000) it works again fine.
Please see the attached images for more.

I would recommend a default value of 8.000 or 16.000.

And Jeroen thank you very much for you work on the new compositor. :)

I think you used opencl to test the chunksizes. certain devices cannot handle the small chunk size. if this occurs in CPU I would consider this as a bug.

Thanks fot the response!

If the chunksize is still a bug, please open another issue.

Thanks for your response!