How to fix an issue of part of a steam game being blocked

Hello Hendrix,

Thank you for detailed answer. I know it took some time to get this all down.

Sadly Windows Security Protection History shows nothing for me to reference.

I've verified game files in Steam for both accounts. No change.

I've signed in with both accounts. No change.

I've tried test by Launching Steam as Administrator. No change.

Is there anything you can suggest? Your efforts are appreciated.

Hi Winston Falkenstein,

Thank you for the update and for trying those steps. Since Protection History is empty, game file verification passes on both accounts, and the issue persists even when running Steam as Administrator, it may be worth checking whether the game's local configuration or user data became out of sync after the block notification appeared.

You could try the following checks:

1, Clear the game's local cache/configuration

• Close Steam completely.
• Navigate to: C:\Program Files (x86)\Steam\userdata
• Locate the folders associated with your Steam accounts and make a backup before making changes.
• Restart Steam and test the game again.

2, Check Windows Security exclusions

• Open Windows Security > Virus & threat protection > Manage settings > Exclusions.
• Temporarily add the Steam installation folder and Master Duel folder as exclusions, then test the game.

3, Test with a new Windows user profile

• Create a temporary local Windows account.
• Sign in, install or launch Steam, and test Master Duel there.
• If it works, that would suggest the issue is tied to the current Windows profile rather than the game files themselves.

I appreciate you taking the time to test the earlier suggestions. Hopefully one of the checks above helps narrow down the cause and gets you back into the game.

Hello Hendrix,

Thank you again for your suggestions. I've tried option 1 and 2 already. It hasn't changed the issue. I'm a bit reluctant to try option 3 and create a third Master Duel profile even if it's temporary.

I think at this point I need to use Get Help. The game file/folder were changed by Microsoft directly per the message because I was switching between the Steam accounts and Master Duel profiles. This doesn't appear to be something I can fix on my end. From what I understand, having multiple Master Duel profiles isn't an issue but it was flagged for some reason.

Hi Winston Falkenstein,

Thank you for the update. Based on everything you've already tried, it sounds like you've ruled out most of the common causes. Since there are no entries in Protection History, Steam's file verification completed successfully, and the issue began immediately after the notification about a blocked game component, there may not be enough information available locally to identify exactly what was changed.

At this stage, contacting Get Help or Microsoft Support is a reasonable next step.

Please note that this is a user-to-user support forum. Moderators, contributors including external Microsoft employees cannot directly intervene in Microsoft product features or access back-end systems. Our role is limited to providing technical guidance on reported issues, requests, or ideas.

You may also want to reach out to the Master Duel support team if you have not already done so, as they may be able to confirm whether a game-specific profile, account association, or connectivity issue could produce the behavior you're seeing.