How to solve “liquibase: Waiting for changelog lock….”?

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:

Ensure OpenSpecimen (Tomcat) process is completely stopped.
Login to the OpenSpecimen database and execute the below DML command to clear the schema lock
```
delete from databasechangeloglock;
commit;
```
Start OpenSpecimen (Tomcat).