Web editor fails to open when trying to resolve merge conflicts

I am unable to use the GitHub web editor to resolve merge conflicts on my remote branches. When I click “Resolve conflicts”, the page tries to load the editor but immediately redirects back to the previous page without opening anything.

This issue started about three days ago, after I enabled some branch protection rulesets. Before that, everything worked normally.

**Steps to reproduce:**

Go to a pull request with merge conflicts

Click `Resolve conflicts`

Page flashes the editor for a moment

Redirects back to the PR page with no editor and no error message

**Expected behavior:**
The merge conflict editor should open normally so I can resolve conflicts directly in the browser.

Actual behavior:
The editor never loads. It redirects back instantly with no error message.

**Additional notes:**
– Issue persists across browsers
– Started happening only after enabling branch protection rulesets
– No changes were made to repository permissions

Please advise if branch protection rules are blocking the web editor or if this is a bug.

No source file or test is identified. Start by reproducing the failure on a pull request with merge conflicts, then compare behavior before and after enabling branch protection rulesets across browsers. Done means the Resolve conflicts action opens the web editor normally and allows the conflict to be resolved without redirecting.

Written by the indexing model from the issue text.