Kanban container has the status ERROR. Signal not possible.

What causes this issue?

The kanban container for which the kanban signal is to be triggered has
the status ERROR. This means, the last kanban signal resulted in an
error and was not triggered as expected.
You must first correct the error before you can change the status.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Proceed as follows:
Analyze the error message for the kanban container.
You can display the error message in the following functions:
Kanban board
Error display
Kanban correction
Eliminate the cause of the error.
Set the kanban container using the kanban correction to the correct
status.

Error message extract from SAP system. Copyright SAP SE.