Unable to launch Apple Diagnostics

Gets more interesting.

The MacBook Pro 2012 boot ROM version and SMC version have been updated (see photo). The boot ROM version is now different to the 226 version that was thought to be the cause of the problem. It is now version 228.

The iMac 2012 boot room version has also been updated - and has a higher version number than the MacBook Pro version. It is now version 285.

The SMC version is however different between the MacBook Pro and the iMac.

I'm not sure that this is good news for the iMac because it suggests that the problem was not with the boot ROM version and may be to do with something more specific to particular hardware. In the case of the 2012 iMac, the hardware is no longer supported by Apple. The 2012 MacBook Pro still is (because it was made/sold until 2014).

What are your concerns?

macOS Mojave - Technical Specifications

General Requirements

• OS X 10.8 or later
• 2GB of memory
• 12.5GB of available storage (OS X El Capitan 10.11.5 or later)*
• Some features require an Apple ID; terms apply.
• Some features require a compatible Internet service provider; fees may apply.

Mac Hardware Requirements

For details about your Mac model, click the Apple icon at the top left of your screen and choose About This Mac. These Mac models are compatible with macOS Mojave:

• MacBook (Early 2015 or newer)
• MacBook Air (Mid 2012 or newer)
• MacBook Pro (Mid 2012 or newer)
• Mac mini (Late 2012 or newer)
• iMac (Late 2012 or newer)
• iMac Pro (2017)
• Mac Pro (Late 2013; Mid 2010 and Mid 2012 models with recommended Metal-capable graphics cards)

https://support.apple.com/kb/SP777?locale=en_US

Your Mid-2013 MacBook Air (MacBookAir6,2) is based on a "Haswell" CPU. All the reports of this problem I've seen so far are from Macs based on the previous "Ivy Bridge" CPU, such as the Mid-2012 MacBook Air (MacBookAir5,2). So you're probably okay to upgrade (if you really want to). (I'm not Apple, and I make no promises.)

Apple altered the EFI to allow the systems to boot up from APFS based drives. If your system is still running a GUID-HFS+ drive then you don't need it. If you try to boot up from an another drive which is APFS then you won't be able to.

So, anyone have news about the Catalina update and UEFI/Apple Diagnostics?

I hope they did update the for the Ivy Bridge models and it's working as it should be.

Everybody had a smooth update having the UEFI problem?

I have an iMac (21.5-inch, Late 2012), so I'm going to hold off on any significant operating system upgrades, like Catalina, until about December, which should allow for enough time to collect any feedback of problems with the new macOS.

This has absolutely nothing to do with the problem reported. I seriously doubt the poster actually read any of this thread.

Some of those suggestions and tools are good, but they won't help this problem in any way whatsoever. I'm pretty sure the problem reported here is due to a security fix put in by Apple and Apple's largess (to be polite) in certifying the diagnostic code so the EFI firmware will run it. The security fix is necessary, BTW. If hackers can execute programs from EFI, they can do really bad things -- it's the same as getting root access.

IMO, none of the advice given will help in this case. This is generic stuff that first level customer support will tell unprepeople to get them off the phone. It looks suspiciously like spam that is being posted to every thread in the forum.

I have to tell that you that even downgrading to OS as old as Lion won't rectify this issue and likely nothing will ever. I never upgraded by following the common approach (installing on top), I always did a clean install on a separate partition: that way I independently run Lion, Mavericks and High Sierra to this day, the last two on an external SSD drive. None of them is able to boot into testsupport.efi. My Mac, in case you've not figured out, is mid2012 MacBookPro. I don't remember when was the last time I ran AHT from Lion which I used exclusively till the end of Dec 2018: it could be 2017 when AHT over the air was accessible. I have to add I've reinstalled Lion about 6 times in the course of the last 6 years I own the machine with the last time being Feb 2018. The strange thing is that just today I navigated to /System/Library/CoreServices in Lion and found .diagnostics folder missing while adhering to the common logic it should've been there. Couldn't it be that reinstalling even such an old system as Lion could modify CoreServices directory if Apple changed something in the recovery version for several Mac models, older than, say MBP 10,1, so that even reinstalling the oldest supported system would strip it of AHT? That's why I think that the last time I ran AHT was 2017.

Of course, I did all the steps mentioned in that post on GitHub: found the compatible AHT disk image, installed that hidden folder to the proper destination, set correct permissions - no result.

It would be interesting if owners of newer machines (2013 and up) chimed in and told us whether Apple Diagnostics is available to them.

when you say you tried both options, can you be more specific?

When trying a new drive did you make sure to do the nvram reset from within recovery?

I have this problem too. Is there a way to confirm that whether Apple tech guys aware of this problem and working on it?

My advice is do NOT upgrade.

I know i am quite late but I have dmgs of Mac OS X 10.7 to 10.15