Description
The specified keyword for horizontal factor type is invalid. Horizontal factor parameters define the relationship between the horizontal cost factor and the horizontal relative moving angle (HRMA). The parameters are composed of a keyword specifying an existing graph or table for a custom graph created from an ASCII file. The keyword parameter can have modifiers, and the entire string needs to be in quotes. Spaces must separate the keyword and modifiers. The format for horizontal parameter modifiers is "modifier_name=value". Valid horizontal keywords are BINARY, FORWARD, LINEAR, INVERSE_LINEAR, and TABLE. Valid horizontal factor modifiers to the keywords are ZEROFACTOR, CUTANGLE, SLOPE, SIDEVALUE, and table_name. For example, a valid horizontal factor parameter is "BINARY CUTANGLE=120".
Solution
Make sure a valid keyword is specified for the horizontal factor. The documentation for How PathDistance works gives more information on the formatting of the parameter file.