Why can't I connect to a VPN?

[AC Question]

Hello,
In any VPN app, I connect and and when the 'Allow Connection' window comes, I can't press 'OK'! I can press 'CANCEL', but not the 'OK' button beside it. Please help me! Are there any missing systemy files? Recently, I deleted 360 Security since I heard someone telling me that it deleted imporant system files. Is that the reason?

 

[christophermccarthy]

Did you pay for the VPN or was it free?