Hi bonsai zovsky,
You need to import another module MxModel Reflection from appstore in your application to resolve this issue.
Refer the documentation to proceed further, https://docs.mendix.com/howto/integration/importing-excel-documents
Thanks!
Hi bonsai zovsky,
The following learning path will guide you the each and every step of configuring Excel Importer Module in mendix app
https://gettingstarted.mendixcloud.com/link/module/142/lecture/1220/4.1-Importing-Data
Regards,
Stella