# CMAQ v5.5 crashes on Day 2 with OPACONC error and “Invalid file name argument CTM\_CONC\_1 **URL:** \ **Category:** WRF-CMAQ\ **Created:** [June 19, 2026, 5:27pm UTC](https://forum.cmascenter.org/t/cmaq-v5-5-crashes-on-day-2-with-opaconc-error-and-invalid-file-name-argument-ctm-conc-1/6243 "2026-06-19T17:27:23Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![oraya](https://avatars.discourse-cdn.com/v4/letter/o/e0b2c6/32.png) [@oraya](https://forum.cmascenter.org/u/oraya)\ **Post date:** [June 19, 2026, 5:27pm UTC](https://forum.cmascenter.org/t/cmaq-v5-5-crashes-on-day-2-with-opaconc-error-and-invalid-file-name-argument-ctm-conc-1/6243/1 "2026-06-19T17:27:23Z")
Hi everyone, I am running CMAQ v5.5 on an HPC cluster. The simulation period is April 2026. I originally had a MEGAN-related issue, but after fixing the restart configuration the model is now able to complete Day 1 successfully and start Day 2. The output files from Day 1 are generated correctly, including: ```auto CCTM_CGRID_v55_gcc_D03_Apr2026_20260401.nc CCTM_CONC_v55_gcc_D03_Apr2026_20260401.nc CCTM_MSOILOUT_v55_gcc_D03_Apr2026_20260401.nc ``` Day 2 starts normally: ```auto Processing 2026-04-02 ``` and a Day 2 concentration file is also created: ```auto CCTM_CONC_v55_gcc_D03_Apr2026_20260402.nc ``` However, the model crashes before completion. The batch log ends with: ```auto MPI_ABORT was invoked on rank 3 in communicator MPI_COMM_WORLD ERROR: CMAQ failed on 2026-04-02 ``` The processor-specific logs show: ```auto *** ERROR ABORT in subroutine OPACONC on PE 001 *** ERROR ABORT in subroutine OPACONC on PE 002 *** ERROR ABORT in subroutine OPACONC on PE 003 ``` Immediately before the OPACONC error I see: ```auto Maximum current record number 4 >>--->> WARNING in subroutine DESC3 Invalid file name argument "CTM_CONC_1" *** ERROR ABORT in subroutine OPACONC on PE 001 ``` My run script contains: ```auto setenv CTM_CONC_1 $OUTDIR/CCTM_CONC_${CTM_APPL}.nc ``` and the output directory exists and is writable. Has anyone encountered an OPACONC crash associated with: ```auto WARNING in subroutine DESC3 Invalid file name argument "CTM_CONC_1" ``` Any suggestions for additional diagnostics would be greatly appreciated. Thank you. ---
**Author:** ![nash.skipper](https://avatars.discourse-cdn.com/v4/letter/n/22d042/32.png) [@nash.skipper](https://forum.cmascenter.org/u/nash.skipper)\ **Post date:** [June 22, 2026, 3:42pm UTC](https://forum.cmascenter.org/t/cmaq-v5-5-crashes-on-day-2-with-opaconc-error-and-invalid-file-name-argument-ctm-conc-1/6243/2 "2026-06-22T15:42:01Z")
Is your second day run failing right at the beginning, or does it run a few hours into the simulation before it fails? Just to make sure, if you have existing output files for 20260402 when you try to restart the model on 20260402, make sure to delete the 20260402 output files first before restarting. If you still see the error after this, please post the error message and maybe 10-20 lines immediately above it from one of the CTM\_LOG files. ---
**Author:** ![a.zarrah](https://avatars.discourse-cdn.com/v4/letter/a/e47774/32.png) [@a.zarrah](https://forum.cmascenter.org/u/a.zarrah)\ **Post date:** [June 25, 2026, 8:27am UTC](https://forum.cmascenter.org/t/cmaq-v5-5-crashes-on-day-2-with-opaconc-error-and-invalid-file-name-argument-ctm-conc-1/6243/3 "2026-06-25T08:27:15Z")
OPACONC calls OPEN3 on CTM\_ACONC\_1. When the previous run was scancel 'd mid-write, it leaves a partial ACONC file (truncated header). On restart, depending on your run script’s disposition setting, OPEN3 it either refuses to clobber an existing file or fails the header-match check, and that surfaces as the ERROR ABORT in subroutine OPACONC. I believe if any partial file or stale log of 2026-04-02 is still there in your output directory, you can clean it and rerun.