This really isn’t the best place to get support, is it?
Just the opposite, in my opinion. Stick around a while and see.
Some of your unknown variables: (to anyone trying to help)
-Are you trying to access your server, from the servers browser?
-IIS or Apache?
-Mod_rewrite or no?
-Are you inside or outside of your own network when it occurs?
“Self hosted” servers have so many different configurations and usually, so many configuration errors at first, that few people will want to try and diagnose your setup problems. Windows? Linux? Mod_rewrite issues? Permalinks or file permissions? Who can say.
From a machine on my network, I just dragged the “press this” link to my toolbar, logged out of WordPress (on a dev server sitting under my desk), then hit the press this link, and it took me right to my log in. The javascript (I believe it is a javascript) worked perfectly, first try. So who can say?
Here is the url my “press this” link used for access just for comparison:
//www.mytestblog.com/wp-admin/press-this.php?u=http%3A%2F%2Fwww.google.com%2F&t=Google&s=&v=2
BUT… this works as well:
//www.mytestblog.com/wp-admin/press-this.php
Your method also worked for me, however all it is doing for me is redirecting and then opening login.php, then press-this.php in a browser window and completely bypassing the javascript popout window.
So you can see why it’s difficult to tell exactly what your particular roadblock may be. Frankly, I don’t think you fixed it. I think you worked around the javascript issue.
Best wishes.