Email rules "Perform the following actions" is vanishing!
I've been having email rules problems for the last few OSs that I recall including the following. In an attempt to reclaim use of Rules in Mail.app, I deleted all rules and started fresh. I pruned the heck out of my saved emails. I emptied the trash bin and rebuilt the mailbox index. I started to slowly rebuild the once-helpful rules, one by one. But the part of the rules creation window, under "Perform the following actions has been shrinking, bit by bit. What the heck is going on here?
Halfway there...
Poof!
iMac 27", macOS 10.13