Flash Player 18 is right now the most popular Flash Player version, and it had the biggest number of installations so far. It has many advantages, and it defines an auto-start registry entry, which means that plug-in will run upon each boot.
While the latest version is version 27, many users still prefer version 18. Usually the latest version is considered the best one because it comes with all the security updates and fixes all the issues. However, users might have their reasons for preferring version 18.
Version 18 might not work anymore
Despite the fact that many users prefer Adobe Flash Player 18, it might be difficult to come across it. This link for it appeared on Reddit and it allowed users to download that version. This link continued to be shared until an issue appeared.
Apparently when a user tried to download version 18, the screen of the computer simply went black. An error message appeared and the user could not find any solution for this problem. However, when the changes were finally reverted and the computer went back to Adobe Flash Player version 26, things returned back to normal.
This raises some doubts. We cannot be sure if something simply went wrong and the user was not able to follow instructions, or there is something that will prevent people from getting version 18 from now on.
It is hard to say yet what was the reason, but if you attempt to download that version you better know what you are doing. It also might be the case that older versions simply do not work anymore since Adobe will remove support for Flash Player in 2020. Since HTML5 is already replacing Flash, we should not worry about this too much.