Eagon questline cannot continue, The operation could not be completed.

https://www.reddit.com/r/pathofexile/comments/1rurpjx/eagon_gets_bugged_if_you_bypass_his_quest_with/

When I try to open a map with Eagon it tells me "The operation could not be completed."

I cannot use memory threads at all on my character. I cannot continue to use maps through Eagon.

I cannot access the map underneath the Eagon node, which prevents me from getting my pantheon completed. Please fix this bug GGG!

Open your map device, and disable whatever beacon is active (Exarch/Eater/Maven).

AFAIK they can't be used with Memory Thread maps until the questline is completed. You've skipped part of the questline by purchasing invites, but Eagon still has you on the questline maps, so it's allowing you to set the beacon but not allowing the map to open with the beacon.