Calculating fields on a pdf form

[defaultl81urhuq5nze]

I need some help with calculating fields. 
i have a PDF form that has up to 50 fields labeled as amounts. And then I have a field labeled "total amount". I need that field to be a calculating one to add up all the 50 other amounts so I can extend the form to my clients. 
When I get to the part where I can modify the field im on to make it a calculating one, when I try to select all the 50 fields to add up, the command just doesn't work and it doesn't acknowledge the action. It just "goes back" to how it was. 

The form was designed by another person for my company and im just trying to edit that to upgrade it for my clients. Can anyone please help me? 

[Asim123]

Can you post your file here?

[defaultl81urhuq5nze]

Im sorry but I cant since it belongs to my company. But thank you for answering anyway 🙂

[Amal.]

Hi there

Hope you are doing well.

++ Adding to the discussion, please check out the help article https://www.adobe.com/content/dam/acom/en/devnet/acrobat/pdfs/js_developer_guide.pdf and see if that works for you.

Regards

Amal

[defaultl81urhuq5nze]

Hi!

Thank you, im going to check it out.

Regards

[ls_rbls]

++Adding to the discussion,

I assume that you're using Adobe Acrobat Pro DC? If yes, which version?

When you open this file in Acrobat Pro, go to "File" --->>> "Properties"

In the dialogue window that will open, click on the "Description" tab.

Down below there's a section labeled "Advanced".

Please provide the information in the line "PDF Producer:"

It is possible that you're working on a PDF that was produced by another program, and the field object that you're working with may have field properties that may not allow editing in Acrobat Pro due to features that may not be compatible in the Adobe Acrobat platform, like for example, an old XFA form created with Adobe LiveCycle Designer.

[defaultl81urhuq5nze]

Thank you very much! I would have never arrived to this on my own, very helpful! I was cracking my head haha

Im gonna try this.

Regards!

[defaultl81urhuq5nze]

Ok so i have checked and the PDF PRODUCER is Adobe PDF Library 10.01 

Apparently it was created with adobe illustrator (coudl that be?)

[ls_rbls]

I am aware that you can't share the file, but would it be possible to share a screenshot of the calculating  field that you're trying to work with?