I believe that you need to talk to your host about this. It sounds like they are blocking the request to show the .htaccess Maker page.
For what it's worth, I have seen this happening on a server and it was ultimately a security rule managed on the host's side blocking all requests with the literal string htaccess in any URL parameter. Do note that the URL for the .htaccess Maker has the URL parameter view=Htaccessmaker as per Joomla's standard behaviour. Once I told them how to reproduce the issue and the exact date and time it happened to me they were able to isolate and disable the rule pretty fast.
Nicholas K. Dionysopoulos
Lead Developer and Director
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