# What this PR does
Handle different failing authentication scenarios (e.g. when token is
invalid or instance context is not a valid JSON) so endpoints return
appropriate response code (401 instead of 500).
## Which issue(s) this PR fixes
Related to https://github.com/grafana/oncall-private/issues/1633
## Checklist
- [x] Unit, integration, and e2e (if applicable) tests updated
- [x] Documentation added (or `pr:no public docs` PR label added if not
required)
- [x] `CHANGELOG.md` updated (or `pr:no changelog` PR label added if not
required)
