Hi Kévin,
As you show in the schema, `emailVerified` is of type `string`. For your update you are supplying a boolean value which we don't support for custom SCIM attributes in 3.1.2 (see "Creating your own attributes" in the [doc page](https://www.gluu.org/docs/ce/user-management/scim2/)).
The exception shown is already giving some clues about this...
To deal with the situation, just pass `"false"` or `"true"`.