I think this is not valid to define a Group with { }. Group is an “endpoint” and will automatically open a new frame containing its members when you click on it.
Either you have not shown us the whole sitemap, or your first “sitemap” line is missing.
Group item=group_house_actualpower
Text item=group_house_sensorbattery
{
...
}
Frame
{
This is the structure it is complaining about.
You cannot have Frames and any other widget on the same “level” or depth of nesting.
Here Group, Text, Frame are all on the same level, this is wrong.
If you think about the UI drawing up each screen, it has to have all Frame boxes drawn which it can then fill in with other stuff, or no Frames at all, just a list of stuff.
Everything is contained within frames.
If you click on the Text {}, it will open up a “new page”. The new page will be rendered in much the same way - two Frames with all content inside the frames.
What you cannot do, is try to do this -
-- Frame --
| Stuff |
-----------
Stuff
You cannot render a page with part frame, part unframed. If there is any frame in this page view, everything shown must go inside a frame.
Each “page” must follow the rules - no frames, or everything inside frames.