Hmmm! Looking at the specs for the HT17 it has a relatively weak processor and much less than half the memory; ROM and RAM, that most other current phones: This could be the clue to freezing photos etc. Even it's Big brother, HT17Pro, has twice as much.
This would also prevent installing Android 7 Nougat, it's just not man enough! Thus you have 2 possibilities-
1 Stop or dump all Apps you don't need, you can also shift some to an SD card, although I note that the HT17 may not support more than a 32 or 64 GB card🤔
2 Spend more than 60 quid on a phone with a faster processor and decent size memory; min 16GB. 🤔
Good luck, Doug 😎

Aha! interesting clue about freezing photos! Missed that 🤔
You can free up a lot of operating memory by stopping or deleting loads of Apps which otherwise run in the background, whether you need or want them or not! Go to the Applications Manager via Settings.
Doing this on my Samsung (and previous Nokia E7) solved a similar problem with photos by MMS and prolonged the battery life enormously 😊 Many Apps regularly 'log in' and check for updates, or report where you are etc., without you noticing. This wastes lots of power 😲
Cheers Doug 😎

Hi Colin and Doug
I have been looking on Google to see if there is any help with upgrading from your phones Android 6.
I could not find a definitive answer but it does appear that the process may require a PC and some good computer skills and knowledge.
If the phone won't update Android via the settings and you have a good connection and phone/internet credit, then it may be above your skillset, and mine!.
As your phone freezes when opening photos I do wonder how much memory you have on the phone?
Doug is correct when he says modern smartphones have made life difficult for many users.
If you bought this locally I would take it back and ask for their advice. My local market has a stall where they perform all kinds of miracles on mobile phones and if I get stuck I usually seek their help.
Dave

Hi Colin, Understand, can sympathise 1000% 🤔
In my opinion, after 45 years in communications electronics including the early days of GSM cell phones in UK, today's 'Smartphones' have been ruined and made dumb by the explosion of useless APPS and the emphasis on advertising revenue.
Only other thing I can think of is that you may need to activate one of the Data Services. Which internet Browser is on your phone and who is your service provider?
Let me ponder some more! 😉
Cheers Doug 😎
PS your HT17 also looks very much like my Samsung J5!

Sorry Doug, followed your advice, but didn't get a newer build on the OS, still won't let me upload photos or answer PM's.
I even tried the Android 7 update app but its full of crap ads and after sitting up till 4am trying to get the update I gave up, as you have to choose to install the rubbish or deny it.
Super frustrated Colin.

Hi Colin,
Go into 'Settings' (press the cogwheel),then 'MORE', then 'About device', then 'Software updates' then 'Update now'.
Make sure you have a good connection (signal strength).
No guarantees this will fix your specific problem but at least you will have all the recent security updates!
Good luck, Doug 😎

Hi silly me. Sorry Android 6.0. How do I update to 7.1
Cheers Colin.

He had written "running Android 6.1" !!

I think Doug means your operating system needs updating to 7.1. Your phone looks remarkable similar to my Iphone 7 so certainly of recent manufacture.
Cheers
dave

Hi Colin, your Android is outdated, update to 7.1.
Cheers Doug 😎