Issues upgrading Craft 2 to 3 - Keep seeing Install Screen not Update screen I'm trying to update my development site on MAMP from Craft 2 to 3. I've installed Composer and tried both upgrade methods (keeping the current directory structure &amp; using the new structure). But with both options, I keep getting shown the install craft screen instead of the update screen. Which is not what I want to do. 

I've added my info to the .env file, but the only way I can seem to get the update screen is by using my old db.php file from craft 2. But then that means that I can use the .env file.

If I then go to complete the update, I tells me that craft can't do a database backup. If I then continue the update to craft 3, when I log in I'm shown the following dependency error:

The auto-generated validation key stored at /Applications/MAMP/htdocs/lorindafontainefarris/craft3/storage/runtime/validation.key has been deprecated. Copy its value to the “securityKey” config setting in config/general.php.

I don't see a validation key to copy, but I already have one that was created for the .env file. Its just not being used because I've used the old db.php file from my craft 2 build. I'm assuming that I shouldn't have to use my old db.php file to get the update to work. 

So can anyone shed some light on why I keep seeing the Install screen when I go to update my craft2 project?

Thanks in advance,

Richard
If you've seeing any install screen instead of an update screen, that means that Craft can connect to the database server specified in craft/config/db.php file, but it either can't find the database you've specified or it can't find the craft_info table.  A common cause of this is the tablePrefix database config setting changed, for example.