Since objects can be appended from 2.5 files into 2.49b, this can be used as a way to get around the lack of copy features in 2.5 and other times can be a lifesaver, let’s look at two examples.
1)-----] You have 100’s of a single object in a level and you want to change some of the logic, well 2.5 doesn’t have the feature where you can copy the logic bricks, don’t panic, there is a way around.
If you have the objects starting with the same name, open 2.49b and append those objects from 2.5 to 2.49, save the file in 2.49 for future use. Change and copy your logic to the 100’s of objects in 2.49, open 2.5, delete the objects in the 2.5 file, then append all the objects back into 2.5, now all the objects have the same logic and in a small fraction of the time.
2)-----] It is now known that making a material to use 2 UVmaps in 2.5 alone will not work, it will show up in the viewport in GLSL view, but will not be displayed properly in the game, the solution is this.
Name your material, then open up 2.49b and append the material to a simple object in that version. The 2nd UVmap should be working properly and the material is how you want it. Save the file and append the material back into 2.5, the good news is that materials using 2 UVmaps that have been saved in 2.49b will work properly in 2.5, after appending the material you can use it on as many objects as you want without it messing up. I’d say the bug is intriguing because the 2nd UVmap will work on materials appended from 2.49b even if appended from 2.5 first, but not materials made from scratch in 2.5. What in the code do appended/ported materials from 2.49 have that materials made entirely in 2.5 don’t?