If you have checked the "Run this program in compatibility mode for" option and selected "Windows 7" or lower OS, you cannot record the Windows Store Apps with the Game Recording Mode.
Please uncheck it or select "Windows 8" and try recording again.
Thank you for your reply.
We are glad to hear that your problem has been solved.
Regarding the other question, creating a new topic would be better.
We look forward to hearing from you again.