You run a migration, and you get the following error:
Unable to remove the index on the field 'Modified' because the list exceeds the list view threshold.
Even if your list view does not exceed the threshold (usually 5,000 items), if a filter is applied to a column that is not indexed, SharePoint might have to load all the items to determine which ones to filter.
For example, you have a list view called Recent items that displays items with a Modified date in the last week.
Even though the number of recent items does not exceed the list view threshold, if your filter is applied to a Modified column that is not indexed, SharePoint will have to load all the items in that list to determine which items to display, which causes SharePoint to return that list view threshold error.
- Use the Built-in view in the View selection drop-down at the top-right of your source items in the migration tool's copy screen. Built-in is a special ShareGate view that loads all your items regardless of the list view threshold.
- Index your column. Open your list settings directly in SharePoint, select Indexed Columns, and Create a new index.
- If you get this error while performing an incremental copy with Copy if newer, use Copy content only instead to migrate your list's content and apply a Time range filter to filter your items so only files from the source created or modified since your last migration are copied. This way, the migration tool will not be affected by the indexing.