The new version of Gradebook throws this error in IE 11
I wonder if we should just use an es6-shim to prevent similar issues like this from happening? This looks like the newest version. https://mvnrepository.com/artifact/org.webjars.npm/es6-shim
Also handsontable might have some IE issues as this wasn't fully tested? Maybe just pull in a simpler polyfill like the findIndex one after
SAK-33715 is udpated. . . Or swap it to ye olde for loop.