I have already downloaded the .zip file from my account, extracted the files and replaced them all in my Runtime. When this didn't work, I contacted the vendor and she had a look at her files and wasn't encountering the problem with her textures. So those two, a corrupted file or vendor error, can be ruled out since I already took measures to rule those out before I posted a topic on the forum. It was Peggy's suggestion that I posted a topic on the forum, since she didn't know what could be causing the problem and her files checked out. (She sent me a screencap to show me.)

It's all very frustrating, with it only happening to this PHC pack and the base product behaves normally, and the strange behaviour making the nodes inaccessible so it's not something I can really work around. Unless I want to be remaking the nodes for that zone every time I want to make a simple change.

Tomorrow I will check on my second computer if the problem happens there as well. Right now, it is 2:37AM and my second system is in dire need of updating before I can check anything.