Error:

Log reader agent has failed with an error

Login failed for user 'sql-user-account'.

Solution:

1. Right click on the publication name and open properties window.
2. Go to Agent Security page and select Security Settings of log reader agent. If the issue in Snapshot agent, select the Security Settings of snapshot agent.
3. Verify the username and password and change it.
4. After the change, the log reader agent runs without an error.