On thing the guys did not explain. Whichever version of UFTree they are using at the moment, they are using the same databases and libraries.
You have UFTree 2.8. There are some nice things in 3.0 that you would like to use, such as global Find and Replace. There are other 3.0 features you want to use. You order version 3.0 at the update price. When it arrives, instead of installing 3.0 over (replacing) 2.8, you install 3.0 into a different directory than 2.8 is presently in.
When you open 3.0, you point 3.0 to where the 2.8 project and libraries are located. Now, both 3.0 and 2.8 can use the same databases. Any changes or additions you add to those databases, using either 2.8 or 3.0 will be saved. Now you can have the advantages of verion 3.0 and have also use the non-buggy 2.8 stuff.
Of course, you need to be sure you have enough space on your hard drive to hold two versions of UFTree, 2.8 and 3.0. Since both versions use (at different times) the same databases, you don't have to worry about having additional hard drive space for the projects, but only need worry that you have enough space to hold two copies of the .exe files, one being 2.8 and the other 3.0.