Web Designer throws the error with "Perform enhance check"

Question

Customer upgraded WD/WP to v7.1.1. When publishing all (Debug), it seems working fine without any errors in web designer. But Web Designer throws the errors with "Perform enhance check" checked. What would cause the errors with PEC enabled? 
 For below errors, what is the recommended guidance to fix the errors? 
 
 Thanks!

Geraldine Hopf · Accepted Answer

You are right, without PEC it will be a warning. 
 
In your custom copy the referenced nodes are not found, so I would try to manually find a node, which does look promising and set the reference there. 
If you don't fix it, whatever is written there, won't be executed. If you tested the behavior of your custom code without the PCE, than you assume it can be deleted.

Geraldine Hopf · Answer

I guess, that this referencing to a config parm... 
If you have not changed it, delete it. 
If it is changed, copy yours, delete it and make a new one with your copy.