This error occurs when the OpenSpecimen process was killed (explicitly) during its bootstrap routine. As a result, OpenSpecimen doesn't get a chance to free the lock that it acquired during the schema update process.

Given below are the steps to solve the problem:

1. Ensure OpenSpecimen (Tomcat) process is completely stopped.

2. Login to the OpenSpecimen database and execute the below DML command to clear the schema lock

   delete from databasechangeloglock; commit;

   
   

3. Start OpenSpecimen (Tomcat).