Can not update latest install on IPadOS 15.8

Without knowing what iPad model you have, certain iPad models, like the iPad Air 2 and iPad Mini 4 are forever stuck to iPadOS 15.8.

These iPad models are over 8 to 9-years old and are simply to old, now.

Sorry.

These iPad models are still supported by third party app developers on the Apple App Store, but look for this to change in the next year, or so.

Third parry app support continues for 3 years, or so, after Apple ends full OS support of a subset of their devices.

You need to consider that it is nearing the end of 2023.

iPadOS 17 is here!

If you need the latest version of iPadOS 17, then you really need to seriously consider a purchase of a new iPad model OR a much, MUCH “newer” and less expensive, refurbished or used iPad models, from better known, trusted sources, like other Apple product/device retailers/resellers, some locally or from online, on the Web/Internet, capable of running the latest iPadOS versions.

There are PLENTY of newer, older iPad models that can run the latest, current versions of iPadOS.

If you need OR ONLY able to afford to purchase older, less expensive iPad models, look at older IPads from 2017 and later.

All of these older model iPads below CAN, currently, run the latest releases of iPadOS 17.

2017, 12.9 inch screen iPad Pro models ( 1st gen Pencil support )

2017, 10.5 inch screen iPad Pro models ( 1st gen Pencil support )

( The above iPad models, probably, are at their last full year of full Apple OS support. )

2018 11 inch or 12.9 inch screen iPad Pro models ( 2nd gen Pencil support )

2020 11 inch or 12.9 inch screen iPad Pro models ( 2nd gen Pencil support )

2018, 9.7 inch screen iPad 6th gen models ( 1st gen Pencil support )

2019, 10.2 inch screen iPad 7th gen models ( 1st gen Pencil support )

2020, 10.2 inch screen iPad 8th gen models ( 1st gen Pencil support )

2020, 10.2 inch screen iPad 8th gen models ( 1st gen Pencil support )

2021, 10.2 inch screen iPad 9th gen models ( 1st gen Pencil support )

2018, 11 inch or 12.9 inch screen iPad Pro models ( 2nd gen Pencil support )

2019, 10.5 inch screen iPad Air 3rd gen models ( 1st gen Pencil support )

2021 10.9 inch screen iPad Air 4th gen models ( 2nd gen Pencil support )

2019, 7.9 inch screen iPad Mini 5th gen models ( 1st gen Pencil support )

2021 8.3 inch screen iPad Mini 6th gen models ( 2nd gen Pencil support )

Get the largest internal data storage model you can afford as NO Apple iOS device has ANY expandable storage.

I am sorry that you had to learn all of this, but this does not change any of the facts regarding these old iOS devices.

Sorry & Best of Luck to You!

If you decide to go down the path of purchasing used, secondhand Apple devices, from individual Apple device sellers, here is how to avoid purchasing an Apple iOS/iPadOS device with user activation lock, in the future.

If you purchase any iPad, or any Apple iOS device, for that matter, used/second hand, online, or even in-person, make sure this iPad does NOT have user activation lock and has been properly reset for sale.

A properly reset for sale iPad should initially power up to an animated, multi-language “Welcome” screen.

DO NOT take the iPad seller's word that this iPad is user activation lock free!

We have seen plenty of used iOS device purchasers get scammed.

User Activation Lock can never be bypasss, circumvented or worked around IF there is no correct previous/original user information to be able to do so.

Apple doesn't get involved with ANY user activation locked, used/second-hand sold devices, either.

So, buyer beware!

If purchasing a used device in-person, power the iPad ON

If the iPad DOES NOT display the initial animated, multi-language “Welcome” screen, then pass on purchasing this iPad.

If the iPad powers up to any other screen, then forget purchasing this iPad.

You cannot trust that the seller actually has the correct needed info to properly reset the iPad back to factory settings right then and there before the actual purchase and exchange of money for the iPad, in question.

Pass on the device!

If you are purchasing this used iPad online ask the seller to provide multiple images, either online or be sent to you via email, showing this animated, multi-language “Welcome” screen of the interested in purchasing iPad model.

Even better, ask for a short video be sent to you showing this animated, multi-language “Welcome” screen, in action and in its entirety, posted to the online ad or emailed to you.

If the online iPad seller refuses any of these requests, pass on the iPad. DO NOT buy!

Good Luck to You!

The iPhone 6 can only be updated to iOS 12.5.7. It lacks components to run newer software. If you want a newer version of software, you will need a newer phone.