vs C#2015 solution's backwards compatibility wont run on vs2010 even when nothing was done to it

Question

so i was in the middle of making a program, when i decided to try upgrading to vs2015 just because i like the newer UI.

so i opened the .sln in vs2015 test run the program again, and re arrange the ui of my program, but i didnt add or remove anything, or even touched the code.

saved the file, and tried opening it again on my laptop that still on vs2010.

i can open the solution,i can access and edit the code, but i can't open the designer at all, or run the program that i made.

although i can also upgrade the one on my laptop to the newer one, im doing this project with a friend that is also still on vs2010, is there any way to make it compatible again?

Answer 1

Whenever you try to open the project in visual studio 2015 which was basically developed in visual studio 2010 will prompt the window for the make some changes in the .sln file also it shows all changes in the browser.

If you try to open that file which is changed by the VS2015 will not be able to open in VS 2010 but available to open in VS 2012 and on word