Document Number: OSUP1012
Product: Observer
Date: 1-23-98 (updated 9-28-99)
Title: OT5050R.DLL and/or MFC42.DLL missing export error

OT5050R.DLL and/or MFC42.DLL missing export error
If you receive an error when trying to start the Network Discoverer Mapping facility regarding either OT5050R.DLL, or MFC42.DLL, this could mean that you have an older version of MFC42.DLL on your system than Observer is designed to run with.

UNFORTUNATELY, there are a number of version of this DLL around - some dated before 6/97 (these are obviously older than the MFC42.DLL shipped with Observer 4.5), and others dated 10/97 that are actually a previous version to the one dated 6/97. Microsoft has cleared up this situation with the latest MFC42.DLL dated 3/12/99 (995,383 kb).

Observer is now shipping with the 3/99 DLL, but if you have an older version (before 6/97) or the “newer” 10/97 version, you will need to replace this with the 3/99 version.

You can download the 3/99 version at:
ftp://ftp1.networkinstruments.com/upload/mfc42.zip

This is a self extracting zip file. Extract the new MFC42.DLL and replace the one that is in your Windows\System directory (best to make a backup of your previous version in case there are any problems).