I have a bunch of dump sql files generated using msqldump command, that I was loading without any error to the version 11.43.15. 

After upgrading to version 11.43.21 to avoid the BBPCheckbats bug, loading the dump started to hang the server. Downgrading back to 11.43.15 fixed the issue.

the command I am using to load the dump:

mclient -d dbname -f sql < "pathtofile/dump.sql"

sample dump file:

COPY 1 RECORDS INTO tablename FROM stdin USING DELIMITERS '\t','\n','"';

Thank you.