This is a simple rule, and I originally had something in the first line but decided it didn't need it. I deleted and now I get the blank line every time. I deleted all triggers and stepped out and then back in. Recreated my trigger again and the blank remains. It is not a huge deal but it looks like the only way I can get rid of it, is to just delete the rule and start over. Which I probably will do because I am mildly OCD and it bothers me when I see it, the rule works BTW.
At this point, re-creating the rule is the only fix, but there is no harm leaving it. However, deleting a trigger shouldn't have caused it; it's more likely that a device in use by that trigger was removed. You can find a few posts on this ("orphaned trigger" and similar terms may help in a search), but here's a summary from the RM author:
Thanks I did some searching but finding the right search term is tricky.
For the future, the bottom of every device page is a list of Appl that device is used in.
I try to remember to check it before removing any device.