When running a workflow, a task that has the "Active" checkbox unchecked in the workflow properties will show blocked even though there are no postconditions that can cause this. All successors will show something like Waiting for Waiting for predecessor.
The successor has a Time & Dependency that has only ENDED_OK and not ENDED_OK_OR_INACTIV
The change will need to be made on the workflow definition. Open the properties for the task directly after the blocked task. Go to the Time & Dependencies tab and update the "STATUS" for the task prior from ENDED_OK to ENDED_OK_OR_INACTIV. This will allow the successor to not be blocked.
See the note in Configuring the Dependencies of a Task in a Workflow:
In the Status & Latest Time Deviations section you specify what will happen if the status conditions defined here or the latest start/end time conditions specified on the Time tab are not met. These are your options:
Skip
The task is skipped but its Postconditions are executed.
The final status of the task in this case is 1930 - "ENDED_SKIPPED - Skipped because of WHEN clause.".
Block
The Workflow blocks at the predecessor task.
If you have previously selected at least one condition matches and none of the conditions is satisfied, the successor task (not the predecessor!) will block the Workflow. The reason is that there is no specific task that is responsible for the mismatch.
Important! Tasks that run in parallel within the Workflow continue processing. The Workflow as a whole is not blocked until all tasks have been executed.
Block and send abort signal to parent
The task is blocked. If there is a superordinate Workflow (parent), a signal is sent that indicates the abnormal end. If this option is set in a Workflow dependency, the parent Workflow remains blocked even after the child task has been unblocked.
Abort
The task and the Workflow itself are canceled.