Probably not relevant but I stopped using frames years ago after I found out that by opening a form file from another project Delphi deleted the frame references (from the DFM???) because the files were not in that project’s scope.
Did not find out for some weeks or months when I tried to recompile the original project.
Gday Vincent,
We have recently encountered this error and just found an answer from good ol’ SO.
TL;DR: You need to add the name (not the type!) of the frame in curly brackets in the DPR file. In our case this ends up looking like:
framepolargraph in 'Frames\framepolargraph.pas' {TngSimplePolarGraph: TFrame},
Before the change, that line looked like:
framepolargraph in 'Frames\framepolargraph.pas' {TtngSimplePolarGraph: TFrame},
Hi Pat
Thanks, but in my case that was already the case - all my frames were listed correctly in the dpr. IT’s a while ago now so I don’t remember how I got past that issue - I just ran it again to check and it’s working as expected.
That said, I migrated the project to 11.3 so perhaps it was a 10.4 bug 
Fair enough. We were having the problem in 11.3 and just resolved it as above.
I just had a look at the code, we never did resolve the issue and resorted to creating the child frames on demand at runtime.