Web survey "failed to submit: - D is null"

[JamesCollins]

I am getting an error "Failed to submit: - D is null" on a web survey.

This problem seems to be related to "file" type inputs on the form. It did not start until I converted some "image" inputs into "file" inputs. The Javascript console logs the following error on submit:

Uncaught TypeError: D is null    
getFilesfromInput https://survey123.arcgis.com/share/v3.11/app-commons-v3.11.20.chunk.js:2
getQuestionVal https://survey123.arcgis.com/share/v3.11/app-render-v3.11.20.chunk.js:2
postOnQuestionValueChangedMessage https://survey123.arcgis.com/share/v3.11/app-commons-v3.11.20.chunk.js:2
markQuestionChange https://survey123.arcgis.com/share/v3.11/app-commons-v3.11.20.chunk.js:2app-commons-v3.11.20.chunk.js:2:193566 
getFilesfromInput https://survey123.arcgis.com/share/v3.11/app-commons-v3.11.20.chunk.js:2
getQuestionVal https://survey123.arcgis.com/share/v3.11/app-render-v3.11.20.chunk.js:2
postOnQuestionValueChangedMessage https://survey123.arcgis.com/share/v3.11/app-commons-v3.11.20.chunk.js:2
markQuestionChange https://survey123.arcgis.com/share/v3.11/app-commons-v3.11.20.chunk.js:2

The survey was first created in March - April 2020, and I'm now resuming work on it using XLSForm in Survey123 Connect v 3.11.123.

I have tried duplicating the survey into a new survey and changing sharing settings. There's no other input validation problems until I get to the last page with the submit button, when I get the "Failed to submit: - D is null" error.

Has anyone else had this issue and been able to resolve? Thanks!

[JamesCollins]

I seem to have resolved the problem. The issue was that I had left the "annotate" option in the appearance field on the inputs I had changed from "image" to "file" type. After removing the appearing option on the file inputs, I was able to submit the form.