"Error: Invalid XRef entry"

[MrShakes]

I am trying to fill some forms on a pdf, as a note I have used both Hummus (another pdf library) and now trying to use this module to fill the form, I was able to successfully read the fields however when trying to write to it I get "Error: Invalid XRef entry", researching this error gave me some hints that the file may be damaged however it opens up and fills properly using Adobe Acrobat Pro.
I've attached the pdf file here fw4.pdf and my code is:

var formValues = { 'topmostSubform[0].Page3[0].f3_18[0]': 'Hello'};

pdfFillForm.write('./sample-forms/fw4.pdf', formValues, { "save": "pdf", 'cores': 4, 'scale': 0.2, 'antialias': true } )
.then(function(result) {
      fs.writeFile("Test.pdf", result, function(err) {
           if(err) {
	      return console.log('Yo: ', err);
           }
	  console.log("The file was saved!");
      });
}, function(err) {
     console.log('Um: ', err);
});

[patrykniedbalski]

I'm having exactly the same message even though, fields are filled. So the only thing im wondering is how to suppress displaying that error.

[lobabob]

I've also gotten the same issue. But I don't see any negative consequences yet (PDF appears to be fine and not corrupt).

[lobabob]

Take that back, there are def negative consequences. In some PDF forms that get this error, PDF properties show up as actual values for some reason. so you end up seeing things like dd or ds in random fields.