Why does a “Project has appeared to have been modified” warning appear (#1) when I click “Install” (#2)?
4D for iOS creates a XCode project (which could be modified/enhanced using XCode or text editor).
Next time you click build it will overwrite that. If some files have a different date the build process opens that warning, in case you modified something, to alert you that you are close to lose that changes.
If you did not modified something with XCode, just click OK. Else use Git or similar to merge your changes.
Another case is when the build failed.
Because a check is done on the Xcode project before build and so its appear as “not conform”.
The conclusion is then that the user had perhaps modified the project.