One of the common causes of an "Unexpected Error Encountered" message if the background value for your data is -INF or negative infinity (-3.4E+0038) or contains NaN values. Some modules aren't able to handle those numbers, even though some data formats now use them as a background values. If a module tries to do multiplication functions on –INF or NaN, it goes out of a valid range and causes an Unexpected/untrapped error.
We have an easy fix for this -- a module called NANFIX. NaN means Not a Number. This module is designed to replace either NaN values or INF or -INF values with a different, user-specified value (e.g. -999).
It will convert all of the INF/NaN values in a single RST file, or in batch mode, it will convert all of the raster files in an input folder, and create fixed files of the same names in an output folder.