Wp-calypso: Posts and Pages can not be edited when SU'd

[senff]

When SU'd as user, it's not possible to view/edit Posts and Pages in Calypso. This started happening late yesterday (October 2).

Steps to reproduce

1. SU as user
2. Go to Blog Posts or Site Pages
3. Select any Post or Page

What I expected

Post or Page can be edited.

What happened instead

Title of Post keeps fading in and out, and at the top right it says "Finishing set up…" in a blue box.

Screenshot / Video

http://prntscr.com/gsvawy

Additional Notes

This only happens when SU. No problems with SSP.

[hoverduck]

It looks like what's happening is that the session is losing its SU status when opening the Editor, and it's hanging because I'm trying to open a post as the wrong user. If I re-SU from the editor page the post loads fine.

We should probably have an error message when attempting to open a post you don't have permissions to rather than just hanging.

[supernovia]

Just noting a similar issue when I go to look at a user's domain server settings while SU'd in as them. Could the same issue be affecting more than just the editor or would you like me to file a separate issue?

[hoverduck]

Likely the same issue. I've removed the Editor label. Thanks, @supernovia!

[sstabrizi]

Just wanted to note a similar issue. When I SU into an account and try to click Settings, I am kicked out of the user account and back to my own. The same message appears that was mentioned above, "Finishing set up…" in a blue box. This only started happening about 3 to 4 days ago. Prior to that, I was able to navigate the user settings without trouble.

[synora]

I just wanted to note that I am experiencing the issue as well. @sstabrizi and I are trial HEs.

[stephanethomas]

https://github.com/Automattic/wp-calypso/pull/18614 has just been deployed, and should fix that issue.

[senff]

Looks like it's working again!