I believe this is due to a change MS have made in the latest version of windows. The dialog itself is an O/S based folder selection one, and they seem to have altered it so that it's now useless.

Can you confirm which version of Windows you are running?

Edit: This actually looks like a bug in the O/S and seems to be OneDrive related. Probably, they will fix it soon. There are workarounds available. See here for more information.

Does disabling OneDrive as described in the above link resolve the issue?

Sorry, there is little I can do to help with this issue.

The dialog in question here is System.Windows.Forms.FolderBrowserDialog. We use this to select a folder for the export option. There are also a few config settings in NCrunch that make use of it.

Under the hood, this dialog uses a Windows Explorer enabled popup intended to select a directory on disk. We haven't changed anything around the use of this dialog in many years, and the code that handles this area of the UI is built into the operating system.

We could simply build our own folder selection dialog, but this wouldn't be aligned with the O/S theme and would be a rather silly thing to do, since it's a service that Windows is supposed to be able to provide. This also won't solve the problem for any other applications running on your machine.

I suggest taking this issue up with Microsoft. They are the only ones with the power to properly fix this issue. A workaround could be to save the NCrunch reports to your desktop, then copy them where you need them to be.