Released on July 9, 2020
If the user opened some estimates or did Check and repaint with them, the error appeared. This happened if the estimate contained multi-column WBS fields from minutes and at least one another WBS field from minutes was displayed on the left of them.
This was a regression problem introduced in QDV 7.19.761 and unfortunately in all 7.20 official. We'll publish soon a fix in the official.