Can't delete file

I can't delete a file. When I click on the following file (assets.http:--www.cafeitaliano.site40.net.plist) it tells me "The name has invalid characters". I tried unlinking the file and uploading a new version of the file but my website still doesn't work. Clicking on my site displays the following: Error 500

An error occurred.

This error may be due to an erroneus .htaccess file, added by you or by a script in the current directory.

To access this directory again you have to correct or delete the .htaccess file. You can do it from the section files management of your control panel by clicking on the gear icon.

I don't know what to do now. Thanks for the help.

[karl94]

You should be able to remove the file using an FTP client. Did you try that?