As per PTC help website
Description
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A config.mech file can be placed in several locations within
the directory structure of a workstation or file network. When
multiple config.mech files exist, Pro/MECHANICA will give priority
to certain files over others. The location of these files and their
priority becomes important when maintaining the desired configuration
settings for a particular user as well as for all users accessing
a single installation of Pro/MECHANICA.
Alternate Technique
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See Resolution below.
Resolution
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Pro/MECHANICA searches in the following order for a config.mech file
upon starting independent, linked, or integrated mode and uses the
options contained in the first file encountered.
1)ThePro/ENGINEERw orkingdirectoryinintegratedmode  ;orthe
directorywhe reindependentmodeisstarted
2)User'shomedirect ory
3)<mech_loadpoint>\<a rchitecture>\lib
It is also important to note that certain settings are saved within
the *.mdb file of a model and will override any config.mech settings,
irregardless of their location. These include the display and orientation
of a model. For example, a linked mode model will appear shaded when
transferred to linked mode, if last saved as such, even if the config.mech
option DISPLAY_SETTINGS_SHADING_MODE has been set to WIREFRAME.
Additional information regarding the usage config.mech files may be found
in the Online Tools Reference or in Pro/MECHANICA Using Structure with
Pro/ENGINEER - "Customizing Pro/MECHANICA Sessions"
