390. NWChem: "Fix collapse/expand in xc_nucder_gen" when using actlist and frequency calc

I ended up with the error in the title when running a job today -- the job does a calc on a complex system, where I'm only interested in optimising and doing normal mode analysis on part of the system. I (am supposed to) achieve this using actlist.

Googling shows the following two posts:
Question: http://www.emsl.pnl.gov/docs/nwchem/nwchem-support/2004/03/0010.Problem_with_Vibrational_frequencies
Answer: http://www.emsl.pnl.gov/docs/nwchem/nwchem-support/2004/03/0012.RE:_Problem_with_Vibrational_frequencies

There doesn't seem to be a follow up between then and now (nine years later).

Note that this is completely different from this post which seems to be due to the OP not putting the actlist in deck A2 (i.e. s/he computes the frequencies for different systems in A and B)

The issue:
The smallest job I can use to trigger this is the following:

scratch_dir /scratch
Title "trigger"

Start  trigger

echo

charge 0
geometry autosym units angstrom
 O     -1.79757     -0.236404     0.264744
 H     -2.77094     -0.198938     0.271156
 H     -1.44498     0.380299     -0.412669
 O     -0.0458786     1.77247     -0.0605460
 H     -0.317322     1.32556     0.781197
 H     0.894700     1.49387     -0.199468
end

ecce_print ecce.out

basis "ao basis" cartesian print
  H library "6-31G"
  O library "6-31G"
END

dft
  mult 1
  direct
  XC b3lyp
  grid fine
  iterations 999 
  mulliken
end

task dft energy
set geometry:actlist 1:3 
task dft freq

Here's the error message:

HESSIAN: the one electron contributions are done in       0.1s

 Fix collapse/expand in xc_nucder_gen        0
 ------------------------------------------------------------------------
 ------------------------------------------------------------------------
  current input line : 
     0:   
 ------------------------------------------------------------------------
 ------------------------------------------------------------------------
 This error has not yet been assigned to a category
 ------------------------------------------------------------------------
 For more information see the NWChem manual at http://www.nwchem-sw.org/index.php/NWChem_Documentation

I can't trigger it with just one water and using an actlist of 1:3 -- seems like I need inactive atoms. However, I've run similar calcs in the past without issue.

The solution:
Do a numerical instead of analytical frequency calculation.

This works:

scratch_dir /scratch
Title "trigger"

Start  trigger

echo

charge 0
geometry autosym units angstrom
 O     -1.79757     -0.236404     0.264744
 H     -2.77094     -0.198938     0.271156
 H     -1.44498     0.380299     -0.412669
 O     -0.0458786     1.77247     -0.0605460
 H     -0.317322     1.32556     0.781197
 H     0.894700     1.49387     -0.199468
end

ecce_print ecce.out

basis "ao basis" cartesian print
  H library "6-31G"
  O library "6-31G"
END

dft
  mult 1
  direct
  XC b3lyp
  grid fine
  iterations 999 
  mulliken
end

task dft energy
set geometry:actlist 1:3 
task dft freq numerical