Sometimes, users see below mentioned /shown error on BlueStacks app player.
"It seems your system has been upgraded. Please click OK to configure and run BlueStacks App Player".
If you receive this pop-up, proceed with steps mentioned below :
(i) Navigate to folder "C:\Program Files (x86)\BlueStacks" and look for "HD-QuitMultiInstance.exe".
Please Note: This is applicable considering your Operating System is installed on "C drive".
(ii) Double click/run the mentioned file.
(iii) Launch App Player again. It should work now.
If you continue getting the issue please download and execute this exe file
If same issue still persists please raise a Zendesk ticket with a brief description.