Like earlier issues with BT Web Mail (still not good for me, though my use of a client insulates me from most of the madness - not an option here!) some customers are seeing no problems (as I am not, now, with BT Cloud) whereas others are in the doldrums.
Almost certainly the new software is clashing with something (or somethings, as the experiences differ) on people's machines, which are not causing other applications/ programmes any problems. With so much on our machines, diagnosing this will be very difficult (and obviously whatever it or they is or are, it or they are not causing problem to other software packages).
Clearly the best first option is to delete the BT Cloud programme completely from your machine, then reboot and try to load the application clean. This did work for me (I had nothing else running at the time) - it did load and now seems to work OK. Previously it wouldn't even load.
But if you've tried that and it hasn't worked for you then I would use this forum to describe exactly what you think is wrong, what system you are running on, and hope the BT moderators will feed back to the programmers. Big generic problems are likely to be fixed before very specific ones, of course. The BT people do know that some anti-virus programmes are rejecting the BT application and are trying to do something about that with the programme owners, (I believe) - but that rejection is not universal across all anti-virus. McAfee and Malwarebytes both seem OK with it, at the moment, or at least are so on my system.
