I'm having a similar problem, so I thought I'd add on to this thread. I have an existing library that I wanted to copy to a new library and change the reference libraries to the new library. I did this using the "copy wizard," and it seemed to work for the most part. However, I have SKILL scripts where I'm trying to create PCELLs in this new library, and I'm running into problems.
I am using an optional input parameter for my script called "dbDelta" which is set at the top of the script (before the "let" statement) using the following syntax: (dbDelta list(1.0 1.0))
It was causing errors that it's never caused before, so I used the setguard() function mentioned above to see where this variable was being changed. The setguard() function told me:
Variable dbDelta set to '('('('('((1.0 1.0)))))) in "(path of script I'm working with)"
It seems that the error is a result of copying the old library to a new library and using the "update instances" option in the "copy wizard". Nowhere in my script am I setting the value of dbDelta other than the top, and if I change the name of dbDelta to anything else, the problem goes away. Thoughts?