Inactive window copies the toolbar of the active one
v11; partially fixed in v12, but the fix is somewhat superficial
Operating system version
Description of the issue
If you have two files with their own custom menus and these menus redefine commands that are duplicated as toolbar buttons (for example, New Record), then when you switch between the files, the inactive file often duplicates the toolbar of the active one. In v11 the toolbar stays active and even runs scripts from the other file. In v12 the toolbar gets deactivated, but it is still copied; one can see this if the buttons have custom titles.
I'll attach a series of screenshots that illustrate how I switch from one file to another and the file in the background copies the toolbar of the foreground file and even run its scripts.
Steps to reproduce the problem
Download the zip file from the following location:
It contains four files, two for v11, two for v12. The files are called Red and Blue and feature a custom menu that redefines the New Record command to be New Red or New Blue respectively.
Open both files (on Windows; I don't know if this is same on Mac and cannot test now). Position them so you can see the New Red and New Blue buttons in both files. Click to bring one or another window to the foreground and see what happens (this doesn't happen every time, but quite often).
The toolbars stay put: the Red file has the New Red button and the Blue file has the New Blue button.
When you switch to, say, Red, the button in Blue changes to New Red. In v11 the button stays active and when you click it, it runs the script from another file. In v12 the button deactivates, so you cannot run a foreign script this way, but the underlying problem is still there: the button in the inactive window changes to mimic the active one.
Exact text of any error message(s) that appear
Windows 7, FileMaker Pro Advanced v11 and 12.
The fix in v12 is a workaround, but it is a rather superficial one. There's no workaround in v11.