It is possible to delete the error log in nShift On-premises. You might want to do this if you have fixed something after getting a lot of error messages. When the log is clean, it will be easier to read the log and see if something is wrong. 

1. In nShift On-premises, go to Tools > Advanced > SQL Explorer.
   
   
   
   
2. Write: delete from errorlog where err_id > 1 and click Execute.