Seems to me trying to get a page ending in
“aich el em el” instead of “aich tee em el” would be a problem all the time.
I’m wondering about the folder named “F colon”
Because you say it’s the home page, and home pages are usually not in a sub folder, I’m guessing that F: is a drive on your localhost and you don’t have things set up correctly?
You must put on your detective hat and try to determine why it happens sometimes and not all the time. What is different between when it works and when it does not.
For example, are all of the files on the F: drive?
From what you posted above, it looks as if you have typed the wrong file name: index.hlml instead of index.html. There will be a problem when you mistype, and not when you don’t.