This bug seems only effect Firefox. If you use some object over the 9patch object, 9patch object's center part seem invisible in some conditions. If you change the size of window (not in construct, in browser) it looks normal again. Another weird thing is, if you preview with run layout button 9patch center part is problematic, but if you use debug it looks normal again.
Edit: I upload a picture.
Attach a Capx
capx is attached
Description of Capx
On the start of layout 9patch is problematic, if you click the next button drawing is refreshed and looks normal
Steps to Reproduce Bug
Center of the 9patch is invisible
Center of the 9patch has to be visible
Operating System and Service Pack
Construct 2 Version ID
Construct 2 Personal r179 64bit Steam
I'm using latest Firefox and it looks OK to me.
Maybe a couple of screen grabs will help to show what your experiencing?
Renders just fine here in Firefox too.
Check your graphics drivers are up to date - it could be a driver bug.
Develop games in your browser. Powerful, performant & highly capable.
I used geforce 340.52 drivers (latest one) also windows is up to date. r179 is buggy but after updating to r180 it works normally.