Adaption project - adding i18n file is not working

Hi experts,

we created a CDS Fiori application, and we like to add an pop-up with a message. We created an adaptation project in BAS for this and added a message text in the i18n.properties file. When we do try to get the text via this.getView().getModel("i18n").getResourceBundle().getText("validateMesage") , we get this error

Assertion failed: could not find any translatable text for key 'validateMessage' in bundle '../../1.84.34/resources/sap/suite/ui/generic/template/lib/i18n/i18n.properties'

We've tried to change the manifest.appdescr_variant by adding 'appdescr_ui5_addNewModelEnhanceWith' and addded the folder ObjectPage under the i18n folder, but that didn't help.

How can we get/add our texts in the adaptation project?

Thanks in advance

Vo