A prompt tells you the version is incompatible and demands that you uninstall it. The Root Cause:
Users running Build 5.9.300 frequently encountered the following critical errors, often preventing the application from launching entirely:
While the 5.9.300 build can be stabilized using the methods above, it is considered a legacy architecture. MSI App Player has since been superseded by newer iterations (often re-branding back to standard BlueStacks 5 or MSI-specific updated variants).