Steps to reproduce:

In Firefox, open: data:text/html,<div role="grid" aria-colcount>Test</div>

Actual behavior:

The HTML document is not accessible and the following traceback is present in the log:

Traceback (most recent call last):
  File "scriptHandler.pyc", line 208, in executeScript
  File "cursorManager.pyc", line 252, in script_moveByLine_back
  File "cursorManager.pyc", line 162, in _caretMovementScriptHelper
  File "speech\speech.pyc", line 1150, in speakTextInfo
  File "speech\types.pyc", line 42, in __iter__
  File "speech\speech.pyc", line 1190, in getTextInfoSpeech
  File "virtualBuffers\__init__.pyc", line 294, in getTextWithFields
  File "virtualBuffers\__init__.pyc", line 283, in _getFieldsInRange
  File "virtualBuffers\__init__.pyc", line 285, in <listcomp>
  File "virtualBuffers\__init__.pyc", line 271, in _normalizeCommand
  File "virtualBuffers\gecko_ia2.pyc", line 90, in _normalizeControlField
ValueError: invalid literal for int() with base 10: ''

Expected behavior:

No error and read "Test".

System configuration

NVDA installed/portable/running from source:

Both

NVDA version:

alpha-24825,4c3a67b2

Windows version:

10 21H2

Name and version of other software in use when reproducing the issue:

Firefox 97.0.1

Other information about your system:

N/A

Other questions

Does the issue still occur after restarting your computer?

Yes

Have you tried any other versions of NVDA? If so, please report their behaviors.

Yes, same behavior.

If add-ons are disabled, is your problem still occurring?

Yes

Does the issue still occur after you run the COM Registration Fixing Tool in NVDA's tools menu?

Yes