How to workaround «This extension was turned off because it's no longer supported» in Google Chrome 138 for extensions based on Manifest V2?

Step 1

Type MV2 in chrome://flags.
2025-07-14--09-46-30

Step 2

Enable the flag #allow-legacy-mv2-extensions («Allow legacy extension manifest versions»).

Step 3

Disable the flags:

  • #extension-manifest-v2-deprecation-warning («Extension Manifest V2 Deprecation Warning Stage»)
  • #extension-manifest-v2-deprecation-disabled («Extension Manifest V2 Deprecation Disabled Stage»)
  • #extension-manifest-v2-deprecation-unsupported («Extension Manifest V2 Deprecation Unsupported Stage»)

Step 4

Relaunch Chrome.