The error comes from the processing of the transition probability arrays for photon
emission.  The JENDL evaluation (that JEFF-3.0 is based on) omitted the isomeric 
state at 1.6334 MeV (which corresponds to MT=53).  This violates Procedure 12 in 
Section 12.2 of the ENDF formats manual.  
The workaround is to put in a section MF=12/MT=53 and set the conditional probability GP
to a very small number:

 8.22070+ 4 2.05198+ 2          2          2          1          0823412 53    1
 1.63340+ 6 0.00000+ 0          0          0          3          1823412 53    2
 0.00000+ 0 1.00000+ 0 1.00000- 6                                 823412 53    3
                                                                  823412  0    4

Also needed is MF14/MT53:
 
 8.22070+ 4 2.05198+ 2          1          0          1          0823414 53    1
                                                                  823414  0    2


The corresponding lines (12/53 and 14/53) should be added also in the MF=1/MT=451 directory
and fix the count of directory lines in that section.