ImageGlass unable to set file extensions

[MT950]

System information:

• Windows OS version: 1909 (OS Build 18363.720)
• ImageGlass version: 7.6.4.30_x64

To Reproduce

Steps to reproduce the behavior:

1. Install Image Glass
2. Go to Settings
3. Go to File Type Associations
4. Click Set as Default photo viewer...
   5.) Optional: Open Windows Default Apps, click "Photo Viewer", ImageGlass will not be in the list, so no way to set it as default photo viewer.

Actual behavior:

Error messages:
The specified registry key does not exist.
Unable to register file extensions for ImageGlass app
Attempted to perform an unauthorized operation.

Expected behavior:

For file extensions to be set.

Screenshots:

[s1099]

You can click on look for another app in pc as shown in image and select the main image glass executable i.e
C:\Program Files\ImageGlass\ImageGlass.exe

[d2phap]

Similar to #1360, it's fixed in v9.0 beta 2!