Bug report

The dataSource filter configuration only accepts string as value.

Reproduction of the problem

1. Open the Dojo example - https://dojo.telerik.com/@martin.tabakov@progress.com/uVAgAYem
2. Open the MultiSelect.

Current behavior

An error is thrown and the MultiSelect does not open.

Expected/desired behavior

There should be no error and the MultiSelect should open.

Environment

• Kendo UI version: 2021.2.511
• Browser: [all]