Errors in sync projects after upgrade from 8.2.1 to 9.1


Hi,

We're performing a series of tests before upgrading our systems to 9.1.  The process ends up flawlessly but the DPR migration processes freeze. Moreover if we try to open a sync project the error message is the same as in sync editor:

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<e>2022-10-26 11:56:03 +02:00 - Error - \IAM-DESARROLLO - VI.Projector.JobComponent.ProjectorComponent - 2b1c2fda-ca05-4057-ae4d-7d859c1b3db9: Errors occurred
[2134007] Could not load synchronization project (CCC-774ED348ED5DA24B97E8AB6289323103)!
[System.Reflection.TargetInvocationException] Exception has been thrown by the target of an invocation.
[System.Reflection.TargetInvocationException] Exception has been thrown by the target of an invocation.
[System.Reflection.TargetInvocationException] Exception has been thrown by the target of an invocation.
[System.Reflection.TargetInvocationException] Exception has been thrown by the target of an invocation.
[System.Reflection.TargetInvocationException] Exception has been thrown by the target of an invocation.
[1777397] Error loading filter of schema class (AdminPrivilege_Master).
[System.TypeInitializationException] The type initializer for 'VI.Projector.Serialization.TypeConfigExport.TypeConfigSerializationBase' threw an exception.
[System.TypeLoadException] Method 'TryConvertFromString' in type 'VI.Projector.Serialization.TypeConfigExport.TypeConfigExportCustomRemoteDataConverter' from assembly 'VI.Projector, Version=9.1.0.0, Culture=neutral, PublicKeyToken=5d0660cde5b231fd' does not have an implementation.
(...)

Database is sqlserver 2019, comp. mode 150 and the administrative workstation is windows 2012 r2 datacenter.