I've just figured out that 'Send an email' feature of the ScriptRunner is not working properly for us. We use it to send an automatic reply to the user with the link to his request (which he files to us by sending an email to a specific mailbox).
When a user sends an email with the following subject:
'"${bamboo.capability.system.git.executable}"' is not recognized as an internal or external command ON AgentIt's all to do with "$bamboo" string in the subject.
JIRA issue does not have transition buttons when created via email with this subject. This 'poisonous' email cannot be removed by JIRA. I had to open the mailbox and remove it. Otherwise, JIRA reads the letter and keeps creating issues that don't have transition buttons.
When I remove this post-function from the workflow everything works as expected - JIRA issue has got all the buttons, etc.