In this image i am not able to press the webpart button to upload a webpart it does'nt mather which webpart , webpart button is disbled!
When trying to Delete an existing webpart i get the following error message like in image 3
try go to this url:
just replace YOURSITE and YOUR_PAGE_WITH_WEBPARTS (e.g. default.aspx) in the URL. It should redirect you to the mgmt page with webparts, where you should be able to delete the problematic one.
Open the web part page in view mode, not edit mode. Then add this to the URL
So, if your URL for the page is
change it to
This will show you a page where web parts on the page are listed and you can select individual web parts and delete them.