New deployment reporting "Request to retrieve adapter schema for adapter with id <x> failed with message A partition could not be found with id <x>"

During initial data load of a new environment I noticed one of my Adapters (for a Connector with 9,761 objects, with only one Transformation, a Time Offset Flag) had pending changes that were not processing.  There were no corresponding errors in the log for it, so I ran Clear Entities, watched the Pending Changes clear to 0, then ran Generate Changes.  At this time nothing was written to the log to indicate processing was under way, but the SQL Server was using 100% of one CPU.  After some time with no evident progress I stopped the UNIFYBroker service, and the SQL Server stopped using CPU.  I restarted the UNIFYBroker service, and the CPU usage returned to 100% of one CPU and this error was written in the log several times.  Since then, nothing has been written to the log and the Pending Changes counter has remained unchanged at 9,761.

Unify.Framework.UnifyEngineException: A partition could not be found with id ae6aa686-33ae-41ba-9462-5f26793f5216.
at Unify.Product.IdentityBroker.AdapterEngine.GetPartitionSchema(Guid partitionId)
at Unify.Product.IdentityBroker.AdapterEngineAuditingDecorator.GetPartitionSchema(Guid partitionId)
at Unify.Product.IdentityBroker.AdapterEngineNotifierDecorator.<>c__DisplayClass6_0.b__0()
at Unify.Framework.Notification.NotifierDecoratorBase.Notify[TResult,TFactory](TFactory notificationFactory, Func`1 action, Action`2 modifyFactory)
at Unify.Product.IdentityBroker.AdapterEngineNotifierDecorator.GetPartitionSchema(Guid partitionId)
at Unify.Product.IdentityBroker.AdapterEngineAccessor.GetPartitionSchema(Guid partitionId)
at Unify.Product.IdentityBroker.AdapterStatisticsEngine.GetEntityCount(Guid adapterId)",Normal
20190719,10:51:30,UNIFYBroker,Unify.Product.IdentityBroker.IEntitySchema GetPartitionSchema(System.Guid),Warning,"Unify.IdentityBroker.Adapter.Engine:
Unify.Framework.UnifyEngineException: A partition could not be found with id ae6aa686-33ae-41ba-9462-5f26793f5216.
at Unify.Product.IdentityBroker.AdapterEngine.GetPartitionSchema(Guid partitionId)
at Unify.Product.IdentityBroker.AdapterEngineAuditingDecorator.GetPartitionSchema(Guid partitionId)
at Unify.Product.IdentityBroker.AdapterEngineNotifierDecorator.<>c__DisplayClass6_0.b__0()
at Unify.Framework.Notification.NotifierDecoratorBase.Notify[TResult,TFactory](TFactory notificationFactory, Func`1 action, Action`2 modifyFactory)
at Unify.Product.IdentityBroker.AdapterEngineNotifierDecorator.GetPartitionSchema(Guid partitionId)
at Unify.Product.IdentityBroker.AdapterEngineAccessor.GetPartitionSchema(Guid partitionId)
at Unify.Product.IdentityBroker.AdapterStatisticsEngine.GetEntityCount(Guid adapterId)",Normal

Could you please suggest what the cause of the error might be, and tell me how to get UNIFYBroker to commence processing the pending changes?

UNIFYBroker v5.3.2 Revision #0
Microsoft Active Directory 5.3.0.0
Chris21 Connector 5.3.0.0
Sync Changes 5.3.0.2
Plus Change Tracking 5.3.0.2
Connections 5.3.0.2
Links 5.3.0.2
Link Statistics 5.3.0.2
Lockers 5.3.0.2
Locker Statistics 5.3.0.2
Provisioning 5.3.0.2
Plus 5.3.0.2

Windows Server 2016 Datacenter + SQL Server 2012 (both UNIFYBroker + SQL running on the same server)