Every time I save and close PD, cupd is working. When I reopen PD, I discover that cupd is suddenly nonfunctional and marked with red borders. As a result, I have to spend two minutes looking up the help document for cupd every time I open PD, so that I can copy the working object back into my patch. What is PD doing to my project between the time I save it and reopen it, and how do I make it stop?

you have to load the ekext library. You can do so by using the [declare] object (look at the help patch), or load the object in the patch: [ekext/cupd]

Okay, thank you.