ERROR: Max egridspec energy=10 above max FEF energy=9.886
mkwarf is required to compute and write a "weightfile" output file which contains FEF regions for use by mkrmf. If the energy range in the input RMF is greater than that in the FEF files, you get an error like:
ERROR: Max egridspec energy=10 above max FEF energy=9.886
Although the comparison to the FEF files is unnecessary in this case, there is currently no way to turn it off (e.g. set the weightfile to "NONE").
Workaround:
In order to avoid the error, it is necessary to define an energy range for mkacisrmf that falls within the boundaries of the FEF files, i.e. approximately 0.28 - 9.8 keV.