Look at this guy, He opened the Creative Mode Backpack in survival.

Pls view this video.

https://twitter.com/cloudy_tao/status/1094801301462867968

Thank you for your report!
However, this issue is Invalid.

The server you are playing on is modified.
If you can reproduce the issue in a vanilla environment, please recreate the issue.

• Any non-standard client/server build needs to be taken up with the appropriate team, not Mojang.

• Any plugin issues need to be addressed to the creator of the plugin, add-on or resource pack.

• If you have problems on large servers, such as Mineplex and Lifeboat, please contact them first as they run modified server software.

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