GUI freezes when I try to write my expression

[Fabio Marzotti]

Hi everyone, I've a really strange problem. I tried everything but nothing change.

When I try to write something on the field where normally I write my expression, the GUI stucks.

The field name is <div class="form-row">.

This happens before (!) click on 'Exceute' button. I'm not able to click on execute because the GUI  is blocked.

I've tried on different browser but nothing change. 

Please do you have some advices?

Thanks, 

Fabio