I tried to make a custom "file not found" page, but it didn't work.

I have an account on a RaQ3.

What I tried is the following: I put a .htaccess file in my /web folder, with a single line like this:

ErrorDocument 404 /custom.html

I also tried the following:

ErrorDocument 404 custom.html
ErrorDocument 404 /home/sites/site55/web/custom.html

Well, none of them worked.

Now I've read in Apache documentation, that for this to work, the server administrator must set the AllowOverride directive for FileInfo.

Is there a command I could use to check if this directive is set on my server?

Was it in the correct web folder with all the other html files? Also, was the custom.html located in the same directory? BTW,

ErrorDocument 404 /custom.html

is the correct way to do it. I have a RaQ3 as well and it works fine.

Yes, I put both .htaccess and custom.html in the "home" directory of my site, where I also have the index.html file.