Fixed It...
Open custom master html file...
get this from header:
<!--SPM:<SharePoint:AjaxDelta id="DeltaSPWebPartManager" runat="server">-->
<!--SPM:<WebPartPages:SPWebPartManager runat="server"/>-->
<!--SPM:</SharePoint:AjaxDelta>-->
Cut it out...
go to the body part... find div with the id "s4-workspace" and paste the code before this div like this:
[...]
<!--SPM:<SharePoint:AjaxDelta id="DeltaSPWebPartManager" runat="server">-->
<!--SPM:<WebPartPages:SPWebPartManager runat="server"/>-->
<!--SPM:</SharePoint:AjaxDelta>-->
<div id="s4-workspace" class="s4-nosetwidth">
[...]
Hope this helps!