To keep the record of the issue as we might need to come back to it at some point
It is a combination when we produce side_output with the centering method and then trying to access that value with a following method (e.g. reconstruction) that is also does the padding. Test to reproduce the issue is probably needed.
A possible workaround to avoid accessing the nonexistent value in OutputRef. This PR pushes the fix, however, the test is not added.
#631