2010 – “Failed to cache field with id” unexpected error on list item edit

Some of our users are receiving “Unexpected errors” when modifying list items. They are third party, but have access to our internal SharePoint site. Our site admin sees “Failed to cache field with id” errors when checking logs.

I am not able to recreate error when doing same change on the list items. This problem is reoccurring for ~5 third party users.

How can I troubleshoot this?

A MS employee mentioned content database size/transaction log space… would this transaction log space change based on end-user saving changes?

Failed to cache field with id “{…}”, overwrite=0

System.NullReferenceException: Object reference not set to an instance of an object. at Microsoft.SharePoint.WebControls.LookupField.Validate() at System.Web.UI.Page.Validate() at System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

Thank you for your time,