Adding A Widget

Hi,
Hope your day is going well!

I’m trying to add a sign-up form to one of my blogs.

I’m putting the html into the text widget, then I click save, and close the text form.

When I leave to look at the form it’s not there.

I go back to the widget page and it’s not saved, it’s gone.

I’ve put many widgets on many blogs, but this has got me stumped.

any ideas?