I'm extending the sitecore experience profile to add a custom tab to display my custom events and facets. i'm following this article:
https://jonathanrobbins.co.uk/2016/04/19/extending-sitecore-experience-profile-speak-app/comment-page-1/#comment-730
However i'm stuck at the step of adding renderings to the "Custom Tab" layout.
or even when trying to edit any of the already existing tabs layout. i always get the following error
i Can't add the placeholders and and DataSource to the new tab i just created.
Any idea what is wrong?