groups rooms GET results in 500

[stoically]

Description

Created the community +containers:mozilla.org with the account @stoic:mozilla.org and now I'm unable to configure it with Riot Web - viewing or trying to edit the community results in an endless spinner.

The network inspector shows that the request to https://mozilla.modular.im/_matrix/client/r0/groups/%2Bcontainers%3Amozilla.org/rooms fails with 500 Internal Server Error and the response is

{"errcode":"M_UNKNOWN","error":"Internal server error"}

Steps to reproduce

• Join +containers:mozilla.org with Riot Web

Version information

• Homeserver: mozilla.modular.im
• Version: 1.11.0

[aaronraimist]

Probably a duplicate of #4891