Follow up from MDL-52661.

Right now when you get an error when editing the criteria for a marking guide (advanced grading) it will not read out on Firefox or IE with NVDA.

Works fine for IE with JAWS and chrome with. We need to look into this and either fix it or make sure it's not a problem on our end (old version on NVDA didn't work on chrome, but upon upgrade it was fixed, so it may be a known bug.)

Jun found the following related but not identical bugs on the NVDA bug tracker:

• https://github.com/nvaccess/nvda/issues/2442
• https://github.com/nvaccess/nvda/issues/2745