Thank you for the excellent instructions.
Line 281 on my test site cmdtest.pw is the same as yours. I followed your directions and was able to reproduce the warning. It has to do with WP Rollback. I looked at the date of the warning and the time (1:15pm Phoenix time). I was testing Caldera Forms issue that day so I could update my support ticket to them.
What I did was update Caldera to v1.8.7. Then rolled back to v1.8.4 and the error appeared again. It don’t think this appears to be something to be concerned with at all. It only happens rolling back a plugin, not updating a plugin.
Is this your thought too? The warning through me off as it’s pointing to a CP file. I was concerned with all the testing of I’ve done for ET and Caldera I had negatively impacted a file.
Those really were great instructions.