its much less now , used to happen when i accessed through proxy , It can get booted when switching ip because they don't log them so maybe your proxy/vpn ?
and for forums being blank , try this as shared by demoakka if its still is blank for u:
Adblock Plus Options > filter list > untick EasyList
and forum work fine, no need to disable adblock totally, just untick easylist from filter list
pop up issue is annoying and is known , its best to use adblock plus addon as Soup says for chrome/firefox browser , make sure you have checked No to "Show advertisement" in settings , make sure you are logging in with ' Log me on automatically each visit' checked otherwise browsing anonymously will lead to these popups
regarding "its only for one day"
its your VIP status that ET gives every new user for a day to try out the benefits of a VIP user , if you want to continue to have the VIP membership , u need to donate bitcoin for it , Site is absolutely free to use for everyone
u can read here more about such Status