I received the following msg:
db_get_version ERROR, file (nul) too short to be BRL-CAD database
db_dirbuild(nul) ERROR, file too short to be BRL-CAD database
Unable to locate where BRL-CAD 7.8.0 data resources are installed
BRLCAD_DATA environment variable [C:\Program Files\BRL-CAD]
BRLCAD_DATA compile-time path 
BRLCAD_ROOT common data path [.]
This release of BRL-CAD expects data resources to be at:
Unable to find 'html/manuals/mged' within the BRL-CAD software installation.
This copy of BRL-CAD may not be properly installed.
What can I do about this? I downloaded the Windows version today (5-30-2006)and installed.
I'm running Windows XP, SP2 on a GAteway PC.
I get the same messages with NT4 SP6, and they
probably appear on every other Windows OS too.
They do not seem to affect the operation so
you can just ignore them until they are fixed.
Or, if they are bother you enough, they can be
temporily fixed in two easy steps. Assuming you
installed in the standard directories, go to
C:\Program Files\BRL-CAD\bin\bat and change
line 17 to "START /B mged.exe" (without the
quotes.) Only one redirection is allowed per
line, so the original line was not redirecting
properly. Then copy or move directory
C:\Program Files\BRL-CAD\doc\html to
There should not be any error messages after
these changes are made.
C:\Program Files\BRL-CAD\bin\bat should be
Had the same using BRL-CAD 7.8.0 on XP. Find the file, .mgedrc, in the root of your %HOMEPATH% (usually c:\documents and settings\username). Open .mgedrc with notepad, and change "Program Files" to "Progra~1" in the following line:
set mged_default(html_dir) C:/Progra~1/BRL-CAD/doc/html/manuals/mged
Resist the temptation to replace the slashes with back-slashes.
Additionally, the key to getting to MGED like your path is to preceed all special characters with an escape slash.
For instance, the only way I have found to make the paths work 100% is:
# Determines where to look for MGED's html documentation
set mged_default(html_dir) C\:/Program\ Files/BRL\-CAD/doc/html/manuals/mged
# Specifies the web browser
set mged_default(web_browser) C\:/Program\ Files/Internet\ Explorer/iexplore\.exe