Sessions Recording page blanks out on errors

[neilkakkar]

Bug description

Any error on the session recording page results in a blank screen.

Specifically, I've noted two cases where this happens:

1. The session ID doesn't exist
2. The request is killed for various reasons (see Some session recordings are huge enough to kill the running process during decompression #4439 )

Expected behavior

An error is shown, and we capture metrics on how often this happens (important for #4439)

How to reproduce

1. Go to: https://app.posthog.com/sessions?date=2021-05-18&sessionRecordingId=1797fff6ff8ca4-0b988ec6c352ab-33687008-13c680-1797fff6ff9899&filters=%5B%5D (undefined if not logged into the right team - 2511; request returns 502 if logged into 2511)

Environment

• PostHog Cloud
• self-hosted PostHog, version/commit: please provide

Additional context

Thank you for your bug report – we love squashing them!

[neilkakkar]

cc: @macobo - thanks for helping me debug!