I've only been using Deepin for a few days and am now trying several applications. Regarding the browser, when trying to open a local file of type aaa.htm, the browser doesn't display its contents... it uses the command "file://home/user/Documents/.../aaa.htm" and I get this message.

This site can't be reached. The webpage at file://home/user/Documents/.../aaa.htm might be temporarily down or it may have moved permanently to a new web address.
ERR_INVALID_URL

I tried the command "file:///home/user/Documents/.../aaa.htm"
and it works. Could it be that the default command to display an .html file is file:///home/....