Wierd behaviour when editting aspx pages in VS

Hi all:

I have VS 2019 community. When I try to edit an aspx page I get a white screen with the message 'En proceso...'(In process..., in Spanish) waiting something.

I was the last two weeks trying to figure out what happens. And don't know it.

It occurs with almost all aspx pages. The codebehind files work perfectly.

Please, can u help  me? had anyone such behaviour?

Thanks in advance.