Yes, the Master Style.
I found this topic:
https://vborg.vbsupport.ru/showthread.php?t=172266
And you told that was the right way.
By the way also triyng to upload the original xml file doesn't work.
tools.php will delete my current styles (I don't want that)?

In that other thread, I am talking about a totally default style (which is a copy of the MASTER STYLE). To make a new default style, you create a new style with no parent. The MASTER STYLE is the style that vbulletin supplies. You will never actually see the MS unless you are in debug mode. The only way to reimport the MS is by using tools.php

I tried but I get exactly the same message (see attachment).
I don't have the new (master) style installed.

Thank you for your time

Ok, I really don't understand what the actual problem is right now. It looks to me like you can add styles. So, *exactly* what are you doing that is causing you problems?

I'm trying to restore the original Default Style (or Master Style, I can't really figure out the difference).
At the end of the process I DON'T have the original style installed, only the 2 styles I already have (AndroidWorld and Mobile Style).

The MASTER STYLE and default style are not necessarily the same. You only see the MS in debug mode. It sounds like you want to see a default style in your list of styles.

Create a new style with no parent:

• Styles & Templates > Style Manager > Add New Style
• Parent Style: No Parent Style
• Title: Default vBulletin
• Allow User Selection: Yes
• Save

Does that work?

Ok, I'm not sure I undestand the difference, but what I want is to get the default vBulletin 4 style that came with the installation.

I already tried the metode you are suggesting me. What I get is the same. I see all the importing/installing process, but than at the end I only see my 2 old style (AndroidWorld and Mobile).

Then you are not doing it correctly. You don't click anything to do with importing/exporting a style. You click the Add New Style button at the bottom of the Style Manager.

I'm having the same issue. Essentially once you overrite the Master Style, you can't get it back.

Using the "leave everything blank and press import" does not work, it runs a script stating that it is building the master style, but then when the list appears it is not there.

Using Tools.php does not work either at this point, same scenario, shows it being built but will not appear on the list.

Thank you,
I solved doing this way.
I'm not a newbie, but this procedure it's a little tricky. Sometime vBulletin is everything but intuitive.
Thank you again!