Hi RolJan,
Greetings from syncfusion support,
Based on your query, we have found that the error occurred
due to the use of a non-Boolean value format in the checkbox field. Please note
that the Syncfusion EJ2 Grid component only supports Boolean values for
checkbox fields. In order to resolve this issue, we recommend either updating
your data to use Boolean values for checkbox fields.
If you
require further assistance, please do not hesitate to contact us. We are always
here to help you.
Regards,
Vikram S