Cubase 7 Side Panel No Longer Opens

I’m running Cubase 7.0.7 on Windows 10. Been running it since January when I had to upgrade from Windows 7 due to discontinued support with no problems.

Today, this happened.

https://youtu.be/oUPm3zSE4EE

The side panel simply doesn’t open anymore. Just finished a song yesterday and it was working fine. There have been no Windows updates. Nothing has changed on my PC since yesterday. The last project, which was working, no longer works.

Here is one odd thing I’ve noticed.

Step 1 - Open up VST instrument.
Step 2 - Click on side panel. Nothing happens.
Step 3 - Open up another VST instrument.

The panel that I clicked in step 2 shows open for the instrument I added in step 3. Trying it in reverse, however (trying to close the panel) doesn’t work. The 3rd VST instrument I load also shows with that one panel open.

This is the strangest thing I’ve ever encountered while using Cubase.

I understand that Cubase 7 is no longer supported on Windows 10 and everybody’s going to just tell me to upgrade, which I will do if faced with no other choice. But I’d like to see if I can get this working again. I see no reason for it to suddenly stop working.

Please help.