Plugins screen locked up

I went to the ‘Widgets’ screen.
I put the Visual Editor Text Widget in the Global Sidebar.
I uploaded a contact form from new widgets.
I copied and pasted the contents of that form into the Visual Editor text Widget in the Global Sidebar.
The text is spilling out over other parts of the Plugins page.
I can’t delete it or close the popup menu from the Visual Text Editor.
The code shows in my website sidebars.
I went back to Plugins and deleted the Form.
The Widgets Screen is still locked up.
Everything on that screen is frozen but I can use my slide-bar to move the whole screen up and down.
How can I unlock the screen and get rid of that data trapped there?