Callback postSystemStartup not working

Hi everyone,

I am trying to register to a callback which gets called after 3ds max has finished starting up using the callback "postSystemStartup" found but it does not get called:

http://help.autodesk.com/view/3DSMAX/2018/ENU/?guid=__files_GUID_C1F6495F_5831_4FC8_A00C_667C5F2EAE36_htm#WS3ED54CBA79FF2E3D-7A802F912B7835E9A3-4CA4

•  I have a "startup.ms" script (I am adding the startup.ms script location to the "PATH" environment variable)

•  in this startup script I am registering a function to the callback postSystemStartup which just prints something.

function test=
(
print "test"
)

callbacks.addScript #postSystemStartup "test()" id:#testid

I tested the setup using a different callback like "preSystemShutdown " and it worked so I think I am doing everythng right.
What I need is a reliable way to execute a script after 3ds max is finished starting up and loading all its plugins.
I also tries to use this "pluginLoaded" but it never seemed to fire.

The reason I need this is so I can savely start to load all our pipeline tools and add them to the menu using Qt methods. otherwise the pipeline menues added get overwritten by some plugin menues like Arnold. I guess it is because I am not using the "MenuBuilder" class. But it would save a lot of code rewrite if I would be able to add our menu using Qt just after 3ds max has finished starting up.

Kind regards,

lukas