HarriK

We've had users report that when trying to launch our apps on Windows they're getting a Blue Screen of Death message relating to cldflt.sys. This is also affecting other apps including Microsoft's Visual Studio as reported on the Microsoft Developer Forums. This BSOD error started appearing after Microsoft released the Windows 10 KB4517389 update.
Microsoft released a Windows 10 update on 10/12/19 (KB4530684) which includes the below fix. Please download and install this update and try opening the Affinity app again to see if your issue is resolved.
Addresses an issue that might cause error 0x3B in cldflt.sys on some devices.

SOLVED!!!
 
With the latest Windows 10 update the Affinity Designer works with OneDrive, as it should.

SOLVED!!!
 
With the latest Windows 10 update the Affinity Designer works with OneDrive, as it should.

To get this out of the way, I do NOT work for Serif nor am I an apologist.
I'm going to dive in on this part only because it may be useful for any non-developers reading, either for this specific topic or generally.
App Store versions (both Microsoft and Apple) of any app are NOT identical to self-distributed versions of those same apps in two critical ways:
There is extra code involved to support the delivery of the app (security & receipt checking, etc) through the respective app store as well as potentially dealing with the environmental differences because of delivery method (see the next point). The "rules" of what an App Store version of an app can do by default are increasingly different than what a self-distributed app may do, predominantly centered around asset and resource access security. "What can you open?", "Where can you save?", "How do you talk to other apps?", "What hoops do you have to jump through to achieve a particular action?", etc. Neither of these is meant to be a "get out of jail free" card for Serif should there be bugs or uncaught misbehaviors due to restriction cases that weren't clear. However, the nature of software development is that the results are imperfect and the more variations there are of an environment, the more likely there will be errors that are only discovered "in the field". Serif, I'm certain, tests for as many of these as reasonable and when something breaks or is missed, works diligently to identify, isolate, and correct those issues.
Add in the nature of App Store business agreements (which effectively are determined by MS and Apple, NOT Serif) and it's understandable that some audiences may feel slighted when there are issues. It's unfortunate, both that those feelings are incurred and that the remedies are fewer for Serif when working with the App Stores but that's the state of the situation in cases like these.

The latest Windows update KB4524570 changed the symptoms, now the blue screen comes when trying to save or open a file.
I have no means to tell who is to blame for the bug, Affinity or Microsoft. At least multiple users having the same setup and path are coming up: Surface, Store, cldflt.sys and OneDrive...
My solution is utterly stupid to use even for a temporarily solution. I am an entrepreneur using my Surface to earn my living. Currently the Affinity software is the only one causing BSOD. I have not experienced BSOD in years with my business laptops.
So far the best solution is to avoid using Affinity Designer and use other graphics tools instead. As I see it, the 50 eur purchase price has granted me right to complain about the matter. I don't even care to calculate what a single BSOD costs for me in terms of wasted working time.