Burp Suite cant perform an Active Scan

Hey guys first of all i wanna say hello to the community im realy glad i found out about kali linux and hopefully more people will :)(Also excuse my bad english im trying my best so you guys can understand me im from Germany btw :) ) Now for my problem. i cant perform any Active Scans with Burp Suite. it also seems it doesnt work right because im getting data in the intercept section i can also use the spider and stuff but somehow i cant perform an active scan. and whats weird im getting data in the intercept section can spider and stuff but in my Browser the page is loading forever. i dont know whats wrong i configured the proxy in my browser but somehow i cant go to any website. and in Burp Suite i cant perform an Active Scan its always greyed out. im realy hoping you guys can help me fix the problem i tried searching the net but i couldnt find a solution. thank you for taking your time reading this block of text i realy appreciate it.

The functions that are greyed out are not available in the free edition. So you will need Burp Suite Pro.