App.ID Inconsistent

Bundle ID either rejected, or forgotten after successful build.
Just moved from RealStudio to Xojo 2013 r3 on Windows 7 PC
ImportedExisting Program - Runs OK
Attempting to Build for Win and Mac. Error message re Bundle-ID required.
Twice has accepted my reverse-DNS format, but frequently rejects it with error message. My format complies with stipulated characters.
When accepted and valid build OK, field reverts from chosen bundle ID to “App” when I move away from App detail then return to it.
Same issue when ported to MacbookPro Retina 13"
Is there a maximum length for bundle-ID?
Why is identical entry sometimes accepted, often rejected?
Why does field revert to “App” when navigate away and back, despite saving and successful build?

What is the bundleID?

I have tried various IDs in reverse-dns format
e.g. com.nauticalsoftware.horizonsim

In case this was too long, I have also tried com.lightmaster.horizonsim

See image at

Does the UTI have to registered with Apple before it can be used in Xojo?

No, and there’s not even a registry for that any more. The old registry at Apple was for the 4-letter code. Those could easily conflict and therefore needed to be reserved. With the UTIs, there’s no fear of conflicts any more if everyone follows the rule to use only names that descend from their owned domain names.

I believe not.

Sounds like a bug or a user error. Make sure you move the focus (cursor) out of the Bundle ID field after you’ve changed that (the same goes for many other edit fields in the IDE!)

Thanks very much for the feedback Thomas. I have just tried, yet again, and made sure I moved out of the Name field. Still gives same error message. As shown in the screengrab referenced above, the ID is all lowercase plus periods.

Everything works fine if only compiling for Windows. Twice out of many attempts it did compile for OSX and on these, the field reverted to “App” as soon as I moved away to a different object and back again.

Any other suggestions or thoughts, please. It is possible I have overlooked something, as I have only just switched to Xojo from RB 2012.

On further thought, the revert to “App” issue might have resulted from failing to exit the Name field, even though I had saved the project. The main problem still remains, of being unable to compile for Mac at present.

BTW, I remember having to submit an ID for another Mac RB project about 18 months ago.


The Bundle ID is placed in the Bundle Identifier field, not the App Name field. The Bundle Identifier field is under ‘BUILD SETTINGS’ within the OSX settings. These are in the Navigator at the bottom.

Thanks very much Simon. Problem Solved

I am still trying to find where everything has been put in the new IDE. App properties are now spread between 3 different locations (at least) rather than all together in one Inspector tab.

What I cannot understand is how it succeeded in compiling a Mac version a couple of times, when I had not put anything in the Bundle ID field.

There is scope for improvements in the help, as searching particular terms more often brings up obscure references than simple instructions or explanation.

No problem.

Ah, should have looked at the screenshot, you’re modifying the name of the App object and I wouldn’t do that if I were you!

Instead, scroll down to the “Build Settings”, and click on the “OS X” checkbox and enter in the bundle identifier in the “Bundle Identifier” box there.