I have been working on a gui tool using GUIDE in 2009b and it has been functional in that environment. After making a trivial geometry edit in 2015b, I was worried to find that while my gui worked flawlessly in 2015b, it no longer could be run or edited in 2009b, resulting in a pile of errors:
??? Error using ==> hgload at 53
invalid Figure file format
Error in ==> openfig at 72
[fig, savedvisible] = hgload(filename, struct('Visible','off'));
Error in ==> gui_mainfcn>local_openfig at 286
gui_hFigure = openfig(name, singleton, visible);
Error in ==> gui_mainfcn at 159
gui_hFigure = local_openfig(gui_State.gui_Name, gui_SingletonOpt, gui_Visible);
Error in ==> testgui at 42
After doing a casual browse of the file contents and creating a test figure file, I notice that 2015b appends a hgM_070000 struct when any edits are made. Deleting this allows the gui to work in 2009b again.
I haven't yet found anything in documentation or bug reports about this. Is there a known incompatibility with older versions of Matlab, or is there something I can do to ensure compatibility beyond manually editing the file contents?
EDIT: After dredging the release notes, I see a long history of deprecated or altered functionality WRT gui development. With that in mind, I suppose it's probably expected that some things in particular are incompatible. The question still stands, though; this change to the file appears to break compatibility regardless of the gui content.
I'm wondering if it's even reasonable to bother using GUIDE as a crutch or if I'm better off just figuring out how to build everything programmatically. Alternatively, I suppose I could always just build the gui in 2009b and never ever touch it again for fear of making it error-bomb other users. If there's an intermediate choice, I'd be interested.