BT isn't likely to help much. So far it has been silent on all BT Cloud problems since the "upgrade" – beyond the occasional message that has been no help in fixing my problems – so you might want to go out and do a wider search for those errors.
One thought is that you could try reinstalling or repairing the Microsoft visual C++ runtime library.
Here are some messages on the topic, but Google shows many many more.
I've got the exact same error as you and it only happened after I "upgraded" their App. As a result I've been trying to speak to someone from BT all morning about it, you just can't get through, when you do speak to someone you just get put back on hold before being cut off.
I suspect they are getting a lot of calls about it.
For the time being I've uninstalled the App and backed my files up on two Flash Drives as an interim measure, but it's just not good enough really.
Let's hope they sort this and admit they've seriously messed up by not testing it properly!
I have exactly the same problem. Also BT Cloud keeps corrupting file explorer and creating many entries of 'Documents' in the LH window. Only solution I have found is to close BT Cloud temporarily.
Just received a BT Cloud update which having installed appears to have fixed the problem!