diff --git a/bld/namelist_files/namelist_defaults_clm4_5.xml b/bld/namelist_files/namelist_defaults_clm4_5.xml
index 678bf29b57..fcb22841bd 100644
--- a/bld/namelist_files/namelist_defaults_clm4_5.xml
+++ b/bld/namelist_files/namelist_defaults_clm4_5.xml
@@ -89,7 +89,7 @@ attributes from the config_cache.xml file (with keys converted to upper-case).
Ball-Berry1987
-lnd/clm2/isotopes/atm_delta_C13_CMIP6_1850-2015_yearly_v2.0_c171012.nc
+lnd/clm2/isotopes/atm_delta_C13_CMIP6_1850-2015_yearly_v2.0_c190528.nc
lnd/clm2/isotopes/atm_delta_C13_CMIP6_SSP119_1850-2100_yearly_c181209.nc
lnd/clm2/isotopes/atm_delta_C13_CMIP6_SSP126_1850-2100_yearly_c181209.nc
lnd/clm2/isotopes/atm_delta_C13_CMIP6_SSP245_1850-2100_yearly_c181209.nc
@@ -97,7 +97,7 @@ attributes from the config_cache.xml file (with keys converted to upper-case).
lnd/clm2/isotopes/atm_delta_C13_CMIP6_SSP534os_1850-2100_yearly_c181209.nc
lnd/clm2/isotopes/atm_delta_C13_CMIP6_SSP5B_1850-2100_yearly_c181209.nc
-lnd/clm2/isotopes/atm_delta_C14_CMIP6_3x1_global_1850-2015_yearly_v2.0_c171012.nc
+lnd/clm2/isotopes/atm_delta_C14_CMIP6_3x1_global_1850-2015_yearly_v2.0_c190528.nc
lnd/clm2/isotopes/atm_delta_C14_CMIP6_SSP119_3x1_global_1850-2100_yearly_c181209.nc
lnd/clm2/isotopes/atm_delta_C14_CMIP6_SSP126_3x1_global_1850-2100_yearly_c181209.nc
lnd/clm2/isotopes/atm_delta_C14_CMIP6_SSP245_3x1_global_1850-2100_yearly_c181209.nc
diff --git a/doc/ChangeSum b/doc/ChangeSum
index 550011e40f..b61ceae1e4 100644
--- a/doc/ChangeSum
+++ b/doc/ChangeSum
@@ -1,5 +1,6 @@
Tag Who Date Summary
============================================================================================================================
+release-clm5.0.25 erik 05/29/2019 Change two files from NetCDF-4 format to NetCDF-3 (because some machines have trouble with NetCDF-4 in pnetcdf)
release-clm5.0.24 erik 05/22/2019 Correct ndep end year for SSPs, 2-degree CMIP6WACCMDECK with C-isotopes off, fixes mksurfdata for high resolution
release-clm5.0.23 erik 05/15/2019 Update cime to bring in CO2 transient files for the CMIP6 SSP's as well as presaero for three of them
release-clm5.0.22 erik 05/08/2019 Fix carbon isotope bug that caused wrong answers for isotopes under transient land-use change
diff --git a/doc/release-clm5.0.ChangeLog b/doc/release-clm5.0.ChangeLog
index 4ae1eebd6c..fad475126f 100644
--- a/doc/release-clm5.0.ChangeLog
+++ b/doc/release-clm5.0.ChangeLog
@@ -1,4 +1,93 @@
===============================================================
+Tag name: release-clm5.0.25
+Originator(s): erik (Erik Kluzek)
+Date: Wed May 29 11:16:13 MDT 2019
+One-line Summary: Change two files from NetCDF-4 format to NetCDF-3 (because some machines have trouble with NetCDF-4 in pnetcdf)
+
+Purpose of this version:
+------------------------
+
+There are two files in NetCDF-4 format that the model uses. Copy these files to NetCDF-3 classic format and point
+to the new version in the CLM XML database (use nccopy -k classic). There are some machines that have trouble with
+reading NetCDF-4 files in pnetcdf.
+
+There are still some NetCDF-4 files for mksurfdata_map, but some of these are required to be in NetCDF-4 format. And we only
+support mksurfdata_map and mkmapdata on cheyenne.
+
+
+CTSM Master Tag This Corresponds To: ctsm1.0.dev025 (with many other changes)
+
+Summary of changes:
+-------------------
+
+Issues fixed (include CTSM Issue #): #734
+ Fixes #734 -- Isotope historical files are in NetCDF-4 format need them in NetCDF-3 or NetCDF-5
+
+Science changes since: release-clm5.0.24
+ None
+
+Software changes since: release-clm5.0.24
+ None
+
+Changes to User Interface since: release-clm5.0.24
+ None
+
+Testing:
+--------
+
+ [PASS means all tests PASS and OK means tests PASS other than expected fails.]
+
+ build-namelist tests:
+
+ cheyenne - PASS (6 tests compare different to baseline)
+
+ unit-tests (components/clm/src):
+
+ cheyenne - PASS
+ hobart --- PASS
+
+ regular tests (aux_clm):
+
+ cheyenne_intel ---- OK
+ cheyenne_gnu ------ OK
+ hobart_nag -------- OK
+ hobart_pgi -------- OK
+ hobart_intel ------ OK
+
+ regular tests (prealpha):
+
+ cheyenne_intel - OK
+ cheyenne_gnu --- OK
+ hobart_nag ----- OK
+
+Summary of Answer changes:
+-------------------------
+
+If the tag used for baseline comparisons was NOT the previous tag, note that here: previous
+
+Changes answers relative to baseline: No! bit-for-bit
+
+Detailed list of changes:
+------------------------
+
+Externals being used: No updates
+
+ cism: release-cesm2.0.04
+ rtm: release-cesm2.0.02
+ mosart: release-cesm2.0.03
+ cime: cim5.6.16
+ FATES: fates_s1.21.0_a7.0.0_br_rev2
+ PTCLM: PTCLM2_180611
+
+CTSM Tag versions pulled over from master development branch: None
+
+Pull Requests that document the changes (include PR ids): #737
+(https://github.com/ESCOMP/ctsm/pull)
+
+ #737 -- Convert the file from NetCDF-4 classic format to NetCDF-3 classic format
+
+===============================================================
+===============================================================
Tag name: release-clm5.0.24
Originator(s): erik (Erik Kluzek,UCAR/TSS,303-497-1326)
Date: Wed May 22 13:33:48 MDT 2019