Battlefield forums are being shut down by the end of the month and will begin rerouting to AHQ - you not being able to log in could just be part of that process.
If you recieved an email regarding a true ban, you'll need to contact the ToS team to sort it out as these types of requests are beyond our control on AHQ
Hey,
If you were banned on the forums, you would receive an email about it. The error message that you get means that you are not able to sign in for some reasons. Check the following:
1) Cache and cookies issues, in this case it's recommended to clear browser cache and cookies.
2) Try different browsers.
3) Also, I couldn't find your forum profile by your name: AdieShine-cn.
Anyway, as was said above, the official Battlefield forums are closing this month, so I'm not sure if it makes sense to fix this problem.
