Cannot fill in fillable form

[urbanl28974291]

I've seen this question posted before, but their solution didn't seem to help.

I got a .pdf as an e-mail attachment.  I'm using Acrobat Pro DC 2020.012.20048.  The document has fillable fields.

When I go to Fill & Sign, I can click on one of the fields.  I see a flashing vertical line.  But, when I start to type, nothing happens.

I've looked at security and other obvious "maybe it's this" places, but nothing comes up.
I assume I'm missing something simple.

What should I check?

Thanks in advance.

[urbanl28974291]

I need to clarify one thing.  
When I try to enter anything by the flashing vertical line, a chime rings - which I assume means the system is telling me I did something wrong.

[try67]

Don't use Fill & Sign. If the file has fillable fields then you just need to click into them in order to input text or a selection.

Fill & Sign should be used when there are no fields in the file...

[Amal.]

Hi there

++ Adding to the discussion

Please look at the help page https://helpx.adobe.com/in/acrobat/using/filling-pdf-forms.html for more information.

Regards

Amal

[Bernd Alheit]

What can you see when you use Tools > Prepare Form?

[JR Boulay]

Can you share your form?

When using Fill&Sign I can fill all fields without seeing any flashing vertical line.