Cannot save landing page draft with incomplete blocks configuration.

Steps to reproduce:
1. Create a landing page
2. Drop a Tag block,
3. Click on Save draft option,

Actual result:
The error popup appears: An error occurred while saving a draft
The error 500 occurred, see the network tab in the browser console.
Expected result:
The draft should be saved without any issues.

Additional info:

{"ErrorMessage":{"_media-type":"application\/vnd.ez.api.ErrorMessage+json","errorCode":500,"errorMessage":"Internal Server Error","errorDescription":"Invalid attribute content in Tag Block. Error message: Content must be set."}}