Issue
An infinite spinner is shown when loading SmartForms (specifically with list views) and/or Management pages showcasing a list of items.
Alternatively, there may be a large delay in loading SmartForms or Management pages that showcase a list of items.
SmartForm Example: 
Management Example:
Error Code
Within developer console you may see the following errors: 
Error 1 Text Output Example:
Uncaught TypeError: Cannot read properties of null (reading 'cloneNode') at SourceCode.Forms.CultureHelper.replaceListCultureNodeWithDetailedCultureNode (SourceCode.Forms.CultureHelper.js?_v=5.1014.22070.1:405:49) at SourceCode.Forms.CultureHelper.<anonymous> (SourceCode.Forms.CultureHelper.js?_v=5.1014.22070.1:86:30) at Object.proxy tas success] (jquery.js?_v=5.1014.22070.1:516:14) at fire (jquery.js?_v=5.1014.22070.1:3047:30) at Object.fireWith ias resolveWith] (jquery.js?_v=5.1014.22070.1:3159:7) at done (jquery.js?_v=5.1014.22070.1:8184:14) at XMLHttpRequest.<anonymous> (jquery.js?_v=5.1014.22070.1:8531:9) at Object.send (jquery.js?_v=5.1014.22070.1:8557:9) at Function.ajax (jquery.js?_v=5.1014.22070.1:8085:15) at SourceCode.Forms.CultureHelper._getCultureNode (SourceCode.Forms.CultureHelper.js?_v=5.1014.22070.1:68:19)
Error 2 Text Output Example:
Uncaught TypeError: Cannot read properties of undefined (reading 'DecimalSeparator') at SourceCode.Forms.CultureHelper.getEditableValue (SourceCode.Forms.CultureHelper.js?_v=5.1014.22070.1:839:47) at applyTableLabelStyleAndFormatting (Populate.js?_v=5.1014.22070.1:1549:68) at new returnStyledColumTextAccordingToType (Populate.js?_v=5.1014.22070.1:1912:20) at populateTableRowFromDefinition (Populate.js?_v=5.1014.22070.1:1385:28) at buildTableRows (Populate.js?_v=5.1014.22070.1:805:27) at BuildTable (Populate.js?_v=5.1014.22070.1:773:13) at rebuildTable (Populate.js?_v=5.1014.22070.1:1952:5) at PopulateView (Populate.js?_v=5.1014.22070.1:307:29) at continueHandleRuntimeBehaviourResult (AJAX.js?_v=5.1014.22070.1:818:33) at handleDoneRuntimeBehaviourResult (AJAX.js?_v=5.1014.22070.1:602:9)
In some cases within a network trace you may see a multitude of AJAX calls running and seemingly never-ending.
Resolution
The above issue could be due to your choice of language within your browser of choice.
To resolve the issue, please ensure you are utilizing one of the supported languages for K2 as per the linked document.
Once the changes to your language settings have been done you should be able to refresh and see the infinite spinners and or loading delays are gone.
If the issue persists please try one of the following:
1. Restart your browser and test again as some browsers require a restart before applying setting changes.
2. Test again with an Incognito or InPrivate window to ensure it is not due to caching that the issue persists.
