If you have time to experiment, what result do you get using FileMaker Pro 15 and the Install Plug-In File script step to install an updated version of a plug-in?
The database has a plug-in table with the Dacon's Mailit plug-in file stored in a container field using external open storage. At log-in, if the version of the plug-in, in the container field, is newer than the currently installed version, the newer plug-in is installed using the Install Plug-in File script step.
Testing with FileMaker Pro on Mac OS X, the Dacon's Mailit v6.0.4b35(dev) is in the container field in the plug-in table. The installed and enabled Dacon's Mailit v6.0.2b31 plug-in is detected and the Install Plug-in File script step executes. The result is:
(1) the existing (older) Dacon's Mailit v6.0.2b31 plug-in remains in place (see URL below for location)
(2) a Saved folder is created and the newer Dacon's Mailit v6.0.4b35(dev) plug-in is moved into the Saved folder (again see URL below)
(3) bypassing the Install Plug-in File script step and manually removing the older plug-in and manually installing the newer plug-in, the plug-in loads and is enabled
(4) amidst the chaos of testing I encountered some other interesting error messages relating to enabled/disabled plug-ins but these are probably symptomatic of the issue in (1) and (2) above
Application = FileMaker Pro 15
Operating System = Mac OS X El Capitan 10.11 and 10.11.5
Plug-In (existing) = Dacon's Mailit v6.0.2b31
Plug-In (new) = Dacon's Mailit v6.0.4b35(dev)
Install Plug-In File script step file locations:
The Install Plug-in File script step executes but the result is the opposite of the expected-and-desired result. The older plug-in is preserved and the newer plug-in is moved into the Saved folder. See attached screenshot showing the end result. The Get Info dialog boxes are arranged to line up with each plug-in: the older file is in the Extensions folder and the newer plug-in is in the Saved folder.
Any experimental results appreciated, either to confirm or contradict my experience, using Apple or Microsoft operating systems and other plug-ins. Thanks in advance.