We are facing "A error occured on the server" issue since 21st May, 2018 regarding all the collections used in our app, Kindly help.

We are facing "A error occured on the server" issue since 21st May, 2018 regarding all the collections used in our app, Kindly help.
This could be due to a number of different items. It could be new columns in your source table or a column changing data types in the source table. Try to refresh your data sources or remove the table(s) and readd them. Then save and close the app to make sure your collection is recreated.