ah, that means you have not yet configured the geoportal to consider myprofile yet. to do so, you will need to edit geoportal\app\context\metadata-editor.js. That file lists the known and used profiles. You will see a list 'allowedTypeKeys' with quite some values. Those values are the keys of the active metadata profiles in your geoportal. You can remove some you don't need and then add "myprofile-iso-19115" to the list.
Then notice the list called 'typeDefinitions'. The entries in this list describe the different metadata profiles by telling geoportal where to find a profile (in the webapp structure) and how to recognize XML to be of the defined profile by an XPath expression ("path"), a criterion ("must":true) and sometimes a value. In that list insert the following JSON object:
{
key: "myprofile-iso-19115",
requiredPath: "app/gxe/types/myprofile/base/DataDocumentType",
interrogationRules: [{
path: "/gmd:MD_Metadata/gmd:metadataStandardName/gco:CharacterString",
value: "MyProfile",
must: true
}]
}