If a plugin either crashes or does not do what you hope, simply delete the .dll from the Effects folder, and you'll be good to go. A plugin will only replace an older version of itself when you download it, not other plugins. If you're questioning an older plugin, just make sure all of your files are saved before you run it. Any plugin you download from this forum is not going to cause unrepairable damage to PDN or your computer.
Also, I believe EER is putting warning messages on the plugins' threads that are known to not work with v4.0.
For help with Quadrilateral Reshape, post in that plugin's thread.