Upload manifest isnt working

Im trying to enable oauth2AllowImplicitFlow, but everytime I try to upload the modified manifest I get this error:

Failed to upload manifest for "AdalPocClient".
ParameterValidationException=Invalid parameters provided; BadRequestException=One or more extension property values specified are invalid.;

I've only changed the property "oauth2AllowImplicitFlow": from false to true.
I've also tried just downloading the manifest and then uploading it again, without any modification. Same result
I've also tried adding a new app to AAD. Same result.

Im following this guide: https://github.com/AzureADSamples/SinglePageApp-AngularJS-DotNet steps 2 and 3

Best regards
Bo