Nothing playing at all- Error message: "Unable to create context"

*I'm submitting a ...*
- [X ] bug report
- [ ] feature request
- [ ] support request

## General information
Running 0.14.0-beta18 on Libreelec Milhouse build 1126 (the latest) on RPi 3B+.

### Description
Since this morning, no videos will play at all. When a video is started an error message is displayed:
Netflix returned the following error: Unable to create context (due to ContentException) for viewableID 80018860.

(The viewableID changes for each video so is presumably a unique identifier.)

Additional info:
Last night I was having difficulties with the Netflix addon in that playback was very choppy with lots of buffering, which is unusual for me as I have very fast FTTH.

### Steps to Reproduce
1. Open Netflix addon
2. Navigate to and select video to play.

Error log can be found at http://ix.io/1uzp

Start by reproducing playback from the Netflix add-on using the listed LibreELEC and Raspberry Pi environment, then inspect the error log at http://ix.io/1uzp and trace the playback path that reports “Unable to create context.” Done means selecting videos no longer produces the ContentException and playback starts normally.

Written by the indexing model from the issue text.