Another thing you can try, which I have had to do a couple times in the past, is completely re-install all of your plugins. Back up your current plugins folder obviously beforehand, delete the contents of plugins/lspdfr, and then install them one by one. To narrow things down even further, test your game out after each plugin is installed. It is very time consuming, but it can help rule out any issues. Also, verify that RPH and Rage native UI are up to date. I would assume you have already done that, but never hurts to check.