For several versions now (since the first version to support Vista) XMetaL Author Essential and Enterprise do not allow writing to files in the install path, typically C:\Program Files\XMetaL...
Newer versions of Windows (after XP) do not allow this unless you reduce their security settings.
So, unless an MCR file is located outside this location (in a location that can be written to) writing to it will not be allowed, and this dialog will disable functions associated with making modifications to any macros in that file.
Configuring XMetaL Author for Local Admin privileges
XMetaL Author Enterprise is installed with the assumption that users have Limited User account privileges under Windows. If you need to set up DITA specializations for your end users, or if you want to enable features that are otherwise disabled for Limited Users you must set the following variable in the XMetaL Author configuration file (xmetal60.ini): user_setting_mode=default
Local Admin users very familiar with the product may continue to work with XMetaL Author Enterprise in this mode, however, we recommend that it only be used to accomplish tasks that cannot be done otherwise and that the default setting be restored once these tasks are accomplished.
The default setting is the "per-user" mode, which is set as follows: user_setting_mode=per_user
