A straight forward new install of osclass 8 was trouble free and registering new users all ok in the database although a form entry for zip/postcode would be useful.

However, when a user edits their user account details the City field does not automatically get re-populated nor does it show the entire A-Z selection when trying to re-select it.

Also, when publishing an item, the city field is again not populated and furthermore, the phone fields are not automatically populated despite being in the database.

Otherwise, Thanks for continuing to develop a great script.

@percyvere
Please provide more info when/how cities/phone number is not populated.
You can provide step by step guide on demo: https://demo.osclasspoint.com/

Partly solved, I now realise the user database s_phone_land and s_phone_mobile are not used to populate the item post form.
This means users have to re-enter data unnecessarily.
For my own convenience to populate the form I have modified /osclass8/oc-content/themes/sigma/item-post.php Line210 <?php  UserForm::phone_land_text(osc_user()); ?> and Line 223 <?php UserForm::mobile_text(osc_user()); ?>

Unfortunately, I still believe there is a bug with user account city inputs which I cannot replicate on your demo site because England is not included in the country selection.
 
On my instalation osclass8/index.php?page=user&action=profile, when updating user records and England is populated, trying to update the city input has issues.

Strangely, the city select populates ok for any city selected up to" Cinderford"  BUT fails to populate for remaining cities despite the correct record existing in the database.

Trying to re-select the city drop down selection list often ends short at "Cinderford" ( i.e. 1266 records) UNLESS England is deselected and reselected which then corrects the select list options all the way to "Zeal Monachorum" (6076 records).

Incidentally, 6076 records is astonishing because it includes towns and villages when in actual fact England has fewer than 100 Cities.

Reverting to a Counties database would be more ideal and an input for Zip/Postcode.

Not following, i.e. this section does not make sense:
Strangely, the city select populates ok for any city selected up to" Cinderford"  BUT fails to populate for remaining cities despite the correct record existing in the database.

City cannot populate city select box.
Demo contains United Kingdom in locations.

When I looked at your Demo Website, the user account and publish pages did not have England or United Kingdom in the Country select input.

Only 3 options ( Россия || abcd || United States )

Unable to select England I cannot test my issue on your demo.

United kingdom has native name set to abcd

OK I think I have found the root of the problem which is causing us both some frustrating confusion.

The NEW locations dataset which is now downloaded from your servers for uk is not the same as your demo.

I can see your Demo appears perfectly ok similar to earlier versions with UK having 30 regions, each having a reasonably small number of cities.
 

However, the new updated dataset included with V8.0 clients such as me in the UK has only 4 regions with England for example resulting in 4827 cities.
This is incorrect and far too large a number because it includes hundreds of small towns and villages.
Consequently, population of the city input select becomes problematic when trying to update the user account etc.

I hope the attached images help to explain.

I can correct this for myself if you don't think it is important for new UK downloads in the future. 

Screenshot of the earlier locations dataset for comparison.

Maybe we could check how to use older regions structure in locations v3.0?
If select box will get thousands of cities, it is bad solution for locations.
In that case is much better to use autocomplete - as used i.e. in Delta theme