Repro Steps
1. Create a build job for a build plan.
2. Add a local agent.
3. Dedicate the agent to perform the build job.
4. Delete the agent.

Expected outcome
The build job will revert back to using any agent to run the task provided it's requirements are met.

Actual outcome
The build job says "No agents meet this job's requirements."

Work around
I can either:

• Clone the job and delete the old one.
• Shutdown Bamboo, backup the Bamboo database and use the below SQL to remove orphaned assignments:

  delete from agent_assignment where executor_id not in (select queue_id from queue) and executor_type='AGENT';