Symptoms

You get one of the following errors in ShareGate Migrate:

This view cannot be displayed because the number of items exceeds the list view threshold defined in your Central Administration. You might need to set indexes on columns with which your view is filtered to be able to load this view.
Unable to remove the index on the field 'Modified' because the list exceeds the list view threshold.

Error code

IN-018-120
IN-452-120

Any error code ending with 120

Details

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.

When ShareGate's migration tool loads your SharePoint items in a migration window, it uses a Built-in view in the view selection dropdown by default.

The view selection dropdown allows you to use your SharePoint views to filter and organize your content.

In SharePoint, the default list view threshold limits the number of items in a view to 5000 items.

You can modify the limit in the central administration of an on-premises version of SharePoint, but you cannot change this limit in Microsoft 365.

You get this error when your selected view surpasses the item limit count of your environment.

The error can also happen with a view that reveals fewer items than the list view threshold with a filter on a column that is not indexed.

This is because SharePoint would have to load all the items in your list to determine which items should be filtered in that view.

There are a few things you can do to work around this error:

Solution

Use the Built-in view in the View selection dropdown at the top-right of your source items in ShareGate Migrate'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 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, ShareGate Migrate will not be affected by the indexing.
If you get the error from an on-premises version of SharePoint, you can increase your list view threshold in your central admin. This solution is not recommended because it can lead to performance issues on your SharePoint server.