Last night one our customers had their development environment updated to Polaris, it all looked good apart from when I opened the case (incident) entity. The form did not load correctly (it was unusable, none of the controls worked) and I received these errors:
SCRIPT5007: Unable to get value of the property ‘focusin’: object is null or undefined
global.ashx?ver=1069248366, line 5 character 58707
SCRIPT5007: Unable to get value of the property ‘SubjectClicked’: object is null or undefined
main.aspx?etc=112&extraqs=%3fetc%3d112%26pagemode%3diframe%26preloadcache%3d1358859637784&pagetype=entityrecord, line 436 character 131
SCRIPT5007: Unable to get value of the property ‘style’: object is null or undefined
form.js?ver=1069248366, line 1 character 22102
After playing around for a while I found the issue was caused by the settings I had for the form assistant.
If the form assistant is enabled but not set to expand by default then I receive the errors.
If I disable the form assistant or set it to expand by default then everything is okay.
So as a work around what I’ve done for now is disable the form assistant and in the meantime raised an issue with Microsoft.