3 Duplicate / Multiple Languages and Currencies after upgrading to 3.30, 3.40 and 3.50!

Hi, I upgraded a copy of our 3.20 DB with source code 3.50, naturally applied the upgrade SQL scripts for 3.30, 3.40 and 3.50 first. No SQL errors, everything else running fine.

However, was a bit shocked to see every currency triplicated, so 3 of everything! Also noted similar for languages - so the  customerlanguage dropdown on all pages has 3 versions of English. Selecting one other than the default makes the buttons and links show ACCOUNT.MYACCOUNT, WISHLIST.HEADERQUANTITY etc - so seems to be a dummy language resource.

This stops our live rollout - I can delete 2 of the languages, but there are many more currencies to remove, plus I can't be sure of the wider impact. Seems to be a bug with the upgrade scripts, ie a DB record issue, not source code. Most likely the scripts are adding key records, not replacing them.

Anyone else had this problem and best way to resolve?

I have the same problem, after an upgrade marathon from 2.50 -> 3.90. Just applied all sql upgrade scripts and now the following entities are duplicated/tripled:
* countries
* currencies
* payment restrictions
* tax classes
* shipping measures

Anyone has an advice what I should do about it? I guess I need to re-play the upgrade and see at which version(s) and find the problem myself. Deleting the entities sounds like a nightmare.

Any ideas?

Oh, I just figured this out.

After re-doing the upgrade scripts from my backup the problem did not appear.

The problem most likely was that I tried to connect a fresh-nopcommerce installation through the "Setup" installation. This failed and I tried 2 times. That installation step probably added these database rows.

One must not run the installation! Instead adapt App_Data/Settings.txt prior to hitting the site.

@nopcommerce owners: This might be a possible improvement: In the setup/installation allow to connect to an existing nopcommerce installation, rather than setting up a fresh installation.

4.0 to 4.1 upgrade from VS2017 - dataSettings.json and installedPlugins.json must be uploaded immediately after the nopCommerce installation page appears. After that, the website should load directly, without the install page. Indeed, if you try to fill the database name, user etc on the install page you'll end with multiple English languages and currencies. So, is a good ideea to backup the database immediately after successfully running the upgrade script.