JMWE shows an error message on the issue view if any error occurs during the execution of the post-function. This message is displayed only if the current user is a Jira administrator.
Delayed execution
Post functions are provided with an option to delay execution for a set number of seconds using the Delayed execution option (Figure 1, right). To delay execution, select the number of seconds to wait until the post-function is run; any value between 1 second (the default) up to a maximum of 20 seconds can be selected.
Workflows that depend on post functions being executed in a specific order can fail due to the asynchronous nature of Connect post-functions in Jira Cloud. One workaround is to delay the execution of a post-function, thereby creating a more predictable execution order. For example, on the approval of a Story you want to create sub-tasks and immediately transition them; in this case, you will have to delay the execution of the Transition Linked Issues post-function, so that the sub-tasks are created before they are transitioned. See the sample use case, below.
Where possible, it is recommended to use the Sequence of post-functions post-function or Shared action post-function to execute a series of post-functions in a specific sequence instead of applying a delay.