Found following error message consol:
Error: script5007 unable to get value of the property 'parentnode': object is null or undefined
svg.js, line 1 character 21336
This refers to "svgweb.removeChild(removeMe,removeMe.parentNode)"
Attached screen shot (with Dutch error message, but you find English translation above )
That code is unchanged from the original firmware, and is pretty much impossible to debug since Asus has obfuscated it by removing any whitespace from the script.