XF 2.1 Xenforo Error

[AccioAce]

Hello, I'm having some strange error issues that I couldn't figure out what is causing it.

1. When I tried to click on the categories from the forum it's given me this message: https://gyazo.com/753824653ce79f4bcce90cecb0370202

2. When I had someone tested by trying to register and I try opening my profile it's given me this error and I can't locate it: https://gyazo.com/811280e418cc49a36eda448732c72ad9

 

[Emre]

1. Check .htaccess file.
2. Can you download the console and pass the error message?