We have upgraded 3 Workflow servers to Workflow 11 Update 3 and didn't have any issues. We upgraded another Workflow server today and we started receiving the below error when Forms would try to contact the Workflow server:

The call to Laserfiche Workflow API was not successful. (Could not load type 'Laserfiche.Configuration.EncryptionAlgorithm' from assembly 'Laserfiche.Base, Version=9.0.0.0, Culture=neutral, PublicKeyToken=607dd73ee2bd1c00'.). [LFF5203-WFServerApiFault]

Details:
URL: 
Error: WFServerApiFault
Date: 2023-11-01 6:27:06 PM (Eastern Standard Time)
HTTP Status Code: 500
Business Process ID: 8
Instance ID: 618134
Business Process Name: CTI - AP - Invoice Approval Forms

Stack Trace:
Caught exception: Laserfiche.Forms.CommonUtils.Exceptions.LFFormsException
Message: The call to Laserfiche Workflow API was not successful. (Could not load type 'Laserfiche.Configuration.EncryptionAlgorithm' from assembly 'Laserfiche.Base, Version=9.0.0.0, Culture=neutral, PublicKeyToken=607dd73ee2bd1c00'.). [LFF5203-WFServerApiFault]
   at Laserfiche.Forms.Routing.LFWorkflowService.Execute(Int32 instanceId, IRoutingContext routingContext, RoutingInstanceStatus OriginalStatus)
   at Laserfiche.Forms.Routing.ServiceTask.Execute(Int32 instanceId, IRoutingContext routingContext)

We tried uninstalling and reinstalling. Republished workflows. Reconfiguring the web services. Nothing seemed to work. So as a last resort we restarted the Workflow server, and everything was right in the world. I thought I would post this in case anyone else came across this error during their upgrades.