Have a look at the start of C:\Program Files\AC3D 8.5.55\lib\tcl8.6\init.tcl
You should see this:
Code:
# init.tcl --
#
# Default system startup file for Tcl-based applications. Defines
# "unknown" procedure and auto-load facilities.
#
# Copyright (c) 1991-1993 The Regents of the University of California.
# Copyright (c) 1994-1996 Sun Microsystems, Inc.
# Copyright (c) 1998-1999 Scriptics Corporation.
# Copyright (c) 2004 by Kevin B. Kenny. All rights reserved.
#
# See the file "license.terms" for information on usage and redistribution
# of this file, and for a DISCLAIMER OF ALL WARRANTIES.
#
# This test intentionally written in pre-7.5 Tcl
if {[info commands package] == ""} {
error "version mismatch: library\nscripts expect Tcl version 7.5b1 or later but the loaded version is\nonly [info patchlevel]"
}
package require -exact Tcl 8.6.10
If you don't see ^^^^^ this line, something is wrong with the installation.