I have used Assets before and everything worked fine but on a fresh install of EE 2.6.1 and Assets 2.1.3 I have the following problem. I have a static index.html file whilst developing the new site. When I click upload and the assets panel is displayed, it shows the content of the index.html. If I remove the html file then the assets panel loads correctly.
Any thoughts on why this is occurring. The only things I have done (as always) is to remove the index.php via htaccess and also rename the admin.php.