I am trying to update the case sla.
whoever created it already had this in place

When i try and change the criteria to the below

i get this error
'
Error code: 0x80040265Session Id: 57b1c1ae-b430-464c-9e82-3f480ad5d9e6Activity Id: c4d6cc43-7799-43d6-9e02-f2fe6e125a87Time: Wed Jul 06 2022 14:52:57 GMT+0100 (British Summer Time)
I cant figure out what it means, the log doesnt tell me which field it could be
Exception Message: Nullable object must have a value.
ErrorCode: -2147220891
HexErrorCode: 0x80040265
ErrorDetails:
ApiExceptionSourceKey: Plugin/Microsoft.Crm.Service.ObjectModel.SLAItemService
ApiStepKey: 94197830-1c25-41b5-a79b-b06a2372405d
ApiDepthKey: 1
ApiActivityIdKey: 920397ad-2b3a-479a-b626-b361955d3dc8
ApiPluginSolutionNameKey: System
ApiStepSolutionNameKey: System
ApiExceptionCategory: ClientError
ApiExceptionMessageName: IsvAborted
ApiExceptionHttpStatusCode: 400
OperationStatus: 0
SubErrorCode: -2146233088
Plugin:
PluginTrace: [Microsoft.Dynamics.SLAManagement.Plugins: Microsoft.Dynamics.SLAManagement.Plugins.PreOperationUpdateServiceLevelAgreementItem]
[5f811bc5-5166-41bd-a818-c9d78ceb4491: Pre validation on SLAItem Update]
Entered Microsoft.Dynamics.SLAManagement.Plugins.PreOperationUpdateServiceLevelAgreementItem.Execute(), Correlation Id: 2e761ed3-22e9-4a57-8dfc-4fe83b584cfd, Initiating User: 7b9eb39a-f60b-ec11-b6e6-000d3ad6a709
Exiting Microsoft.Dynamics.SLAManagement.Plugins.PreOperationUpdateServiceLevelAgreementItem.Execute(), Correlation Id: 2e761ed3-22e9-4a57-8dfc-4fe83b584cfd, Initiating User: 7b9eb39a-f60b-ec11-b6e6-000d3ad6a709
TraceText:
[Microsoft.Dynamics.SLAManagement.Plugins: Microsoft.Dynamics.SLAManagement.Plugins.PreOperationUpdateServiceLevelAgreementItem]
[5f811bc5-5166-41bd-a818-c9d78ceb4491: Pre validation on SLAItem Update]
Entered Microsoft.Dynamics.SLAManagement.Plugins.PreOperationUpdateServiceLevelAgreementItem.Execute(), Correlation Id: 2e761ed3-22e9-4a57-8dfc-4fe83b584cfd, Initiating User: 7b9eb39a-f60b-ec11-b6e6-000d3ad6a709
Exiting Microsoft.Dynamics.SLAManagement.Plugins.PreOperationUpdateServiceLevelAgreementItem.Execute(), Correlation Id: 2e761ed3-22e9-4a57-8dfc-4fe83b584cfd, Initiating User: 7b9eb39a-f60b-ec11-b6e6-000d3ad6a709
Activity Id: c4d6cc43-7799-43d6-9e02-f2fe6e125a87
Any help would be appreciated
Thanks