Query with SUM() erroring - /rowgroup.h@677: assertion '0' failed

Customer reported error

We have a 2 UM, 2 PM system and running version 1.2.3 . We came across an error in the one of our processes that had been running for some time with no errors (has run since the upgrade to 1.2.3 successfullyl). I attached the full support report. The error requests to contact support:

cat err.log from um1

Apr 1 09:13:17 Calpont[115953]: 17.308918 |0|0|0| E 00 CAL0000: /data/buildbot/bb-worker/centos7/mariadb-columnstore-engine/utils/rowgroup/rowgroup.h@677: assertion '0' failed
Apr 1 09:13:17 joblist[115953]: 17.309070 |78252|0|0| C 05 CAL0000: IDB-2035: An internal error occurred. Check the error log file & contact support.