To compile and run Drawing Viewer you must have the OpenDWG libraries (they are free). ADINIT.DAT is one of the files supplied by the OpenDWG Alliance. Although it is not part of the OD link libraries, it is a file which is required to be present in order to run the Drawing Viewer. It should be placed in a directory called "OpenDWG" which should be located below the directory containing the executable. If Viewer cannot locate this file an error message will show on the screen and you will not be able to proceed.
If you have any custom font files (*.shx) files these may be placed in a directory called "fonts" which should be located below the directory containing the executable.
If you receive a font file with a drawing and do not ever expect to use it again, or you do not want to clutter up your fonts directory, you may locate the font files in the same directory as the drawing file. Viewer will look for fonts there also.
Be sure that the case (capital or lower) of the font is correct. If a font is not being loaded then the most likely cause is a mismatched case. If Viewer cannot locate the proper font then it will substitute its own and write a message to that effect to the text window. You may use the F2 key to toggle the text window up and down.
At the current time Viewer will only look for XREF's in the same directory that contains the drawing being viewed. Remember this program is still a Drawing viewer and not a production CAD program.