What i did to fix this was view the SQL that was being executed instead of executing them. I then copied these SQL details to a file and removed the DROP SEQUENCE line. Then ran the SQL file by connecting to the database using the psql, which is is a command found in the m2ee. I then ran the following code to run the SQL file on the database.
\i somedir/script2.sql
After this i restarted the server and synced the model and it worked again.