Compared to the SNMP Collection profile in the Desktop launcher, you browse from you local file system instead of from your hard disk when you select an MIB file to import into the SNMP Collection profile.
To open the SNMP Collection Profile, click the Configuration button in the upper left part of the Desktop window, and select SNMP Collection Profile from the menu.
SNMP Collection Profile - Open File dialog when loading MIB files
In the MIB Workspace area, click the Load MIB Files button. In the Open File dialog, click the Browse button. Select the required MIB file. The file populates the MIB Workspace.
For further information, see SNMP Collection Profile, but note that the user documentation is written based on when you are using the Desktop Launcher.