I asked in discord a while back about this. I am not on the PC that I am having the bother with so I cant give a log, which I know might not help anyone. On my PC Reborn buddy works with no problems. But when I am on the other PC the frame rate drops and hangs all the time. I can not use it for combat assist. I can use it for crafting though as although the screen lags, it still seems to be able to produce items/craft rotation fine. On the discord, someone said it was a known issue with a nvidia graphics card or something? I updated all the graphics card drives but its still unplayable while running. Is there a known fix for this then? Sorry, I don't have a log. I won't be on that PC for another week or so.
If you have a system with G-Sync turn off G-Sync. Or if you have VSync on turn that off. (note these are two different things, G-Sync is a technology with nvidia cards on supported G-Sync capable monitors) Make sure you don't have any other Overlay / Screen Capture things running. (discord overlay, x-split, obs) your antivirus might be doing something. there is a huge list of applications that can interfere with RB in the wiki somewhere.