During upgrade from pre-Polaris family versions (Rome and prior) to Polaris family versions (San Diego+), forms with embedded lists are broken - Known Error

During upgrade from pre-Polaris family versions (Rome and prior) to Polaris family versions (San Diego+), forms with embedded lists are broken Description Forms with embedded lists are temporarily broken during the upgrade from a pre-Polaris (Rome and prior) version to a Polaris (San Diego and later) version.

Steps to Reproduce

Pre-requisites: A pre-Polaris (e.g.: Rome) instance 1.) Navigate to a form with an embedded list (e.g.: "Change Request" change_request.do form with the "Conflicts Detected") embedded list 2.) Kick off an upgrade to a Polaris/Next Experience enabled family release (San Diego, Tokyo, Utah)

Expected behavior: During the upgrade, forms with embedded lists work as expected

Actual behavior: During the upgrade, forms with embedded lists are broken (UI Policies not applying, reference icons unclickable, etc), and the following error can be observed in the console while on such forms.

Uncaught Reference Error: isPolarisTemplate is not defined at js_includes_listv2_doctype.jsx?v=01-27-2023_1724&lp=Wed_Nov_02_09_32_29_PDT_2022&c=34_966

Workaround The current workaround is to clear the instance cache (cache.do) shortly after the beginning of the upgrade.