Why is this not working even when I comment out every line of JavaScript?

Question

I had no problems on Google Chrome or Microsoft Edge. Not even a warning. Yet on SoloLearn all I seem to get is a blank screen and after a few minutes, a generic ‘Syntax Error.’ Even when I comment out all the JS, the pure HTML doesn’t display either, which is strange. Previous version at least displayed, so it’s even more strange. Is the <noscript> or the IE code it doesn’t like? That’s what’s new. And the uninitialized variable error in the previous version is also strange. I would really appreciate some insight on what’s happening. (This is my first major web code).

https://code.sololearn.com/W2jT9jed5UuS/?ref=app
https://code.sololearn.com/W8II69bfCC8b/?ref=app

Answer 1

I finally found the problem with “Why can’t all the browsers agre??”! Removing the iframe on lines 176 - 177 fixes it! At least for me.

Answer 2

Jason Stone Thanks so much! I guess iOS is more picky about non-existent files. I’m going to upload it somewhere eventually, but I haven’t yet.