This article is from the Apple II GNO FAQ, by Devin Reade with numerous contributions by others.
A#11.2: This is an indication that the files 13/OrcaLib, 13/SysFloat, and 13/SysLib are not properly matched. You cannot mix these files from different versions of ORCA/C. The OrcaLib shipped with GNO can only be used with particular versions of the other two libraries. You should (re)read the section in this FAQ on "Installing GNO with ORCA".
 
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