StudioX project cannot open: "Invalid structure, ActivityBuilder implementation is missing"

Hi, I created a StudioX project and saved it.

I tried to open it later and got this error

The project [path] could not be opened: Project is incompatible with StudioX profile. You can open it in Studio and fix the errors.
Invalid structure, ActivityBuilder implementation is missing

I didn’t make any changes that would have made it incompatible? Also, I can’t open it in Studio since my license (Free) doesn’t have access to Studio, so how do I actually fix it?

Was able to reproduce and find a workaround.

This issue comes about when you have set one or more Arguments to Required. For some reason this will cause the project to break.


  • Open the Main.xaml document in the root of your project folder, using Notepad or something else.
  • Inside the <x:Property> tags that are set as required, delete the tags that denote the argument as required:
        <RequiredArgumentAttribute />
  • Save the file and you should be able to open the project in StudioX again.

Rather bad bug and really annoying that 1) required arguments are broken, 2) the error message doesn’t help at all (had to do a lot of digging to reproduce), and 3) that it tells you to use Studio to fix it when you can’t use Studio as a Free user, meaning most people will just think their file is broken and give up. Or worse, recreate their file from scratch, and then run into the same issue, wasting all that time.

1 Like


Thank you for this finding , we raised a bug and we will have a fix in the next release. Just out of curiosity what version of StudioX are you using :slight_smile: