This is new in Roma-0.3.0, and I'm guessing it _might_ be related to https://github.com/TEIC/romajs/issues/101. When an ODD is create from scratch in Roma, removing (some) inherited attributed classes throws an `uncaught exception: [object Object]` error. Following steps illustrate the issue: 1. start with TEI Minimal schema 2. select `<persName>` 3. delete `att.datable.custom` from `<persName>` This throws the error mentioned above. Note: the same error is thrown when `att.datable.iso` is removed. Yet, removing `att.datable.w3c ` does work.