Can't open project after DDC location change and engine upgrade

I changed my derived data cache location to an external drive using the editor preferences method and deleted the one that was already in use. Now after the change, i’m unable to open my project, which hangs on 95% and is not even compiling shaders when i check in the taskbar. Also, tried deleting intermediate and saved folders in the project. But even that doesn’t help. And what more, after an engine upgrade, i am now** unable to create even a new empty project**, which stalls at 35% or so. Any idea where and what went wrong and how to go about resolving the issue. Upgraded from 4.25.0 to 4.25.3. Thanx in advance.