Getting this sync related error on Appian Community edition

I created a simple RecordType and defined relation with User for createdBy and modifiedBy. I added recordlist to new Site. It was working few days back. Today I am getting the following error.  Nothing has changed in last few days. 

The Requested Record Type Is Not Available Expression evaluation error [evaluation ID = HE53D] at function a!recordList: An error occurred while retrieving the data for "User". Details: Record type is marked as synced, but its data has not yet been synced or its existing synced data has been invalidated. Contact your system administrator. (APNX-1-4198-000). 

Synced the recordtype few times through manual or data edits through data preview screen. Please help me with why this is happening today?