Getting a index error when rendering a Mosaic

[shipswake]

When I render a Mosaic layout in react I receive the following error:

Warning: Each child in a list should have a unique "key" prop.

Check the render method of InternalMosaicWindow. It was passed a child from MosaicComponent. See https://reactjs.org/link/warning-keys for more information.
at RemoveButton (http://localhost:3000/static/js/vendors-node_modules_react-mosaic-component_lib_index_js.c1881da8.js:9979:42)
at InternalMosaicWindow (http://localhost:3000/static/js/vendors-node_modules_react-mosaic-component_lib_index_js.c1881da8.js:9371:47)
at ConnectedInternalMosaicWindow (