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User needs to generate new access key. Go to Settings page and remove current key by clicking on “Disconnect GitHub Account“ button. Then re-connect as before. you will be granted new valid key.
Troubleshooting
Company GitHub accounts may have blocked OAuth apps or some other security features that may interfere with GitHub integration. Typical for these errors is that content visible for the user in GitHub is not displayed in the plugin.
If you experience such issues please set organization approval for OAuth apps and approve OAuth apps for your organization.