Message 'Could not start publishing process' when publishing to Adobe DPS in Content Station 9

When trying to publish an issue to Adobe DPS from Content Station, the following message can appear:

Could not start publishing process

This can happen when trying to publish an issue while another user is already publishing it.

Under normal circumstances, the publishing process should be completed after a short period of time (depending on the size of the issue and the connection to Adobe DPS). The issue should become available for publishing after the process has been completed.

In case the publishing process results in a more serious technical error (in PHP or Enterprise Server), the issue is made available after 10 minutes.