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iMazing IPA restore strange fail
Tried iMazing with a couple of old ipa files and most were installed flawless on my „new“ Air.
But some of the older ones failed in the middle of the process with an error dialog telling: couldn’t be installed because the CPU of this device is not supported.
It cannot be related to the apps because I‘ve run them on an Air-2 in IOS-13.
No success with Google, as everybody seems to be about side-loading atm.
Any clues ? (it‘s about PPG Wave Generator and Wave Mapper) 
Comments
They're probably 32-bit apps. iOS no longer has the code to run 32 bit apps.
thanks, makes sense... though the error message is quite misleading.
I just checked on the Air-2 (13.6) and both PPG apps are running fine.
The iMazing target Air-1 was on 12.5.
Leaves making an ipa from the installed versions as an exercise to the reader...
The reason the Air-1 is stopped at iOS 12.5 is that it has 1 GB processor memory, and iPadOS 13 required a 2 GB processor. Maybe the IPA version you have is "too new" for the older device and it actually cannot be installed.
And you cannot make an ipa from the installed versions. You can only download an ipa from the AppStore. You need to catch the working version before it goes out of fashion.
The ipa files are from an old iTunes backup from around 2015, probably from an iPad-2.
(content of the folder Mobile Applications)
So 'making an ipa' means just a faint hope I might have an iTunes version that doesn't reject the Air-2 on 13.6.
It's not about saving 30bucks for iMazing... if someone confirms iMazing can restore the PPG apps in their most recent shape, I'd just go for it. But if that would fail, I'd be mighty disappointed
Independent from this specific case iMazing seems to be a great toolbox.
You don't need to pay iMazing for restoring .ipa files, this feature is unlimited in the free version. You can make as much app backups as you want, and restore them as may time as you want.
Also, iMazing is not the only option for restoring .ipa files, Apple has an official app for this. With Apple Configurator 2 in your Mac, you can restore these .ipa files. But you can't make backups from the app store with this, so it's only useful if you already have the .ipa files backed up.
Worth also noting that iMazing does have an "extract ipa" functionality but I don't know how reliable and functional it is as I haven't tested it.
If your ipa is that old, it's likely a 32-bit app, and I believe iOS 12 was already 64-bit only, so your old ipa cannot be used, and the original unsupported CPU message was correct. Basically, your iOS version is too new to run this old ipa.
Yes, of course that‘s correct in technical terms... but pointing explicitely to the CPU (while the app was perfectly running on an even never CPU) simply puzzled me. Oops...
Some of those apps were updated during their lifetime at the store, so all was fine on the Air-2.
@Pynchon thanks for enlightening me about the free features
Conclusion by self: read carefully... the message didn‘t complain about the CPU, but about the CPU-Type
Succeeded... the full backup didn‘t take long and then transfers can be handled by switching between device and library (no ipas visible, but the action was identical).
Choose an app, select download (Apple ID password entry), iMazing downloads it to the library (pool of apps from all your devices, if they‘ve been connected) and then the Install button transfers it to the currently selected iDevice.
Just as written on the web page...
But no rule without exception: I‘ll have to transfer my old CZ-Touch ipa again, as the downloaded „most recent version“ failed to work, no numbers, no activity, just frames and circles on the GUI. The old ipa (yesterday) was ok.
Downloading „off-store“ apps may take a couple of retries, btw. Seems it doesn‘t get access to the files at 1st attempt (only occasionally).
Feels good to have the PPG and Holderness apps in safe harbour now, thanks again for support
ps: for completeness about that exception: iMazing didn‘t restore the original CZ Touch app, but Touchbase with the CZ modules included (as intended by the developer)