Update to 7.1.5 without losing members / data

Our Dolphin dashboard says to update to 7.1.5. Last time we paid someone to do this for us and they somehow deleted all of our members and data. 

What is best way to update without losing any modifications we have made to our website and to our mobile app? We do not want to lose any members, data, or modifications.

Secondly, when will Trident be ready? Will it be easy to update our 7.1.5 to Trident? Will Trident integrate with same Dolphin mobile app, or is it an entire,y different app?

If it is any help we have just upgraded our site from 7.0.3 to 7.1.5 without losing data of any kind.

We were helped by a contributor here called Denre.

Some of the modifications we made were lost because the core code has changed over the years but it is not hard to sort out that problem.

Indeed, an upgrade should NEVER do that. They dun goofed bad, and I hope there was a backup.

First, always make a backup before starting an upgrade. Check with the developers for any third-party modules and templates to make sure they're compatible before starting the upgrade. And for source-mods, check the patch ZIP to see if a modified file will be overwritten. If so, make any changes to the new file. Then follow all the instructions in the docs and the upgrade script.

In the case of 7.1.5, only about three system files are modified, and these are usually not used by mods. So if this is a 7.1.4 site, it shouldn't be a big operation. There are no database or file changes for modules.

For Trident, there's no ETA, as work re-focuses on Dolphin. As they are different scripts, there's no direct upgrade path, but BoonEx has said that a migration script is planned, so most data should be able to be transferred from a Dolphin to Trident site.

If you're going to use Boonex and Dolphin, you really need to teach yourself some basics. A simple upgrade like this is very easy to do if you follow the instructions.