Patch #10, fixes the issue.
Testing steps:
1. Remove the primary menu block a...

Patch #10, fixes the issue.
Testing steps:
1. Remove the primary menu block and then look at the JavaScript Console.
Got two js error messages in console Uncaught TypeError: Failed to execute 'getComputedStyle' on 'Window': parameter 1 is not of type 'Element'.

Testing results:
Patch applied #10, No js error messages in the console.
Added before and after patch screenshots for reference.