Version

0.4.1

Sketch version

51.2

What is expected?

Clicking "Update" button in Sketch plugins pane or in Runner updates the plugin.

What is actually happening?

Nothing.

How to repreduce this problem?

Try updating from 0.4.0.

The error log from Console.app when the problem occurred

Not necessary. It isn't working because you neglected to add the plugin archive to the release. It's that simple.