Jim Day
Ansys Employee

I spoke to the developer of *INITIAL_ALE_MAPPING.  He replied,

"I would say that the 1st integer in the mapping file is not properly read (either it has been created with a double precision executable or the file is somehow corrupted or the file has indeed been created by *BOUNDARY_ALE_MAPPING) ".

If that doesn't help, if you hold a commercial (non-academic) Ansys/LS-DYNA license, he suggested you provide the input and mes* files for debugging.   Do this by filing a Service Request or by contacting your Ansys Channel Partner.   You can't provide files via the Learning Forum.