Saving Mosaic Layouts with RichText

When I save some Mosaic Layouts, everything works except the RichText tile(s).
(the text has disappeared)

Has anyone seen this before ?

No I haven't seen this before.

Which Plone/plone.app.mosaic versions are you using?
It is reproducable on certain texts/layouts or random?

I use Mosaic 2.2.3

It does not happen on all layouts, but I have not figured out 'what combinations that does this yet.

It could be that it happens when I have more than one tile / fragment that contains rich text in the same layout.

Update: (I updated the site to 5.2.3 to see if that matters)

When I save a Mosaic layout I get Unicode error.
If I "Customise" the layout and does nothing, the unicode error goes away.

So I assume it has something to do with saving and 'checking if something is text or binary'…

… to be continued…

Update (maybe solved):

I removed the widget definition and added a lot of namespaces. That seems to work. This is the richtext part that is working now:

<?xml version="1.0" encoding="UTF-8"?>
    <model xmlns:easyform="http://namespaces.plone.org/supermodel/easyform"
      xmlns:form="http://namespaces.plone.org/supermodel/form"
      xmlns:i18n="http://xml.zope.org/namespaces/i18n"
      xmlns:lingua="http://namespaces.plone.org/supermodel/lingua"
      xmlns:marshal="http://namespaces.plone.org/supermodel/marshal"
      xmlns:security="http://namespaces.plone.org/supermodel/security"
      xmlns:users="http://namespaces.plone.org/supermodel/users"
      xmlns="http://namespaces.plone.org/supermodel/schema"
      i18n:domain="medialog.dutchestheme">
    <schema>
      
    <field name="text" type="plone.app.textfield.RichText" marshal:primary="true" >
          <title>Text</title>
    </field>

    </schema>
</model>

PS: I removed all the other fields that are present in my code ( title, description, link, button text etc )