Error when combining files created with restart in a CALPUFF simulation

[nininini]

Dear CALPUFF Users,

I am trying to use APPEND (v7.0.0) to combine CONC.DAT files generated with CALPUFF v7.2.1 using the restart capability. Each file corresponds to a fragment of the same simulation, generated with the same executable.

When I run APPEND with these files, I get the following in the console:

STOP Halted in RDWR1 --- See List File

And in append.lst I see:

ERROR -- Header record data do not match!

Observations:

The visible headers (NSRC, NSRCTYPE, LSGRID, LCOMPR, etc.) appear identical between the files.

If I run APPEND on a single file to extract a subset, it works correctly for any of the individual simulation periods.

My questions are:

Has anyone else encountered this problem when combining files generated with restart?

How can I fix this, or what is the recommended way to combine CONC.DAT files without APPEND stopping due to this error?

Thank you in advance.