Recently I worked on one of the issues where PWA Administrator was not able access the PWA and was getting below error.
The last thing he did was start a Delegation session to act as one of his team member.
We were able to login as another user by using the the URL as http://servername/pwa/_layouts/closeConnection.aspx?loginasanotheruser=true. This indicated that there was no issue with PWA site and it’s up and running.
Later we verified the team member’s security settings and found that team member was not part of any security group. We added him to Team Member group and that fixed the issue. As Team Member was not part of any security group the delegation session was not getting initiated when administrator started the delegation session to act as Team Member.
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