Quote Originally Posted by jiji2018 View Post
The version I am currently using zencart1.55f is 2.0.5
Want to upgrade to the latest 2.1.2, directly overwrite old files?
Another question is that the 2.1.2 version can perfectly support the 1.55F version of zencart?
I hope to get a serious reply
You can safely overwrite the files that OPC provides in its distribution. Whether or not v2.1.2 can perfectly support your zc155f installation depends heavily on what other plugins you might have installed, especially the template that you use.