Microsoft Store still has issues in Windows 10 v1903
Despite Microsoft trying to fix the majority of the issues with cumulative patches, some of them were missed. After a couple of serious problems that affected the MS Store in Windows 10 build 18950, a new one has emerged.
This is a new one: Upgrade to Windows 10 Version 1903 toasted the Appx Store, Windows is losing its mind and filling the WindowsTemp folder with Store logs to the point of the disk being full, 16MB per log, multiple logs a minute.
Store logs can fill up your drive in just a couple of minutes
This is a big problem because the logs are pretty big at 16MB, and a full hard disk slows down your PC considerably and can lead to other unwanted issues.
The culprit seems to be a broken Windows Push Notifications database, and many users couldn’t solve the issue without making a new user account.
Another possible fix is to open %LocalAppData%\Microsoft\Windows and rename/delete the Notifications folder.
It’s worth mentioning that this isn’t a widespread problem for now. Microsoft isn’t aware of it and hasn’t addressed it yet, so there’s no confirmed resolution.