The error seems to be caused by some other problem which blocks the initialization of the workflow services.
1. Open Sitefinity.log file located under App_Data folder and clear it.
2. Restart the application.
3. Try to publish a content item/page. An error will be thrown and written in the log.
4. Attach the log file to the thread.
Also could you please give me some more information about your project - your setup and if you have any customizations to Sitefinity's workflow. Any additional information is welcome.
the Telerik team
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