Open Transport v1.0.8 activates AppleTalk, which causes the -97 error. This issue is addressed in Open Transport v1.1. The System 7.5 Update 2.0 should solve this problem. There are several applications which O.T. 1.0.8 activates AppleTalk including MegaPhone, PageMaker, and Quark Xpress. However, there may be other applications this also occurs with.
Solution
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Use the System 7.5 Update 2.0 software to update your version of Open Transport to v1.1.
This article was published in the 8 April 1996 Information Alley.