Please help, I cant get past this validation error:

ERROR DETAILS
Error Text: Unit of Measure Code must have a value in Sales Line: Document Type=Invoice, Document No.=102234, Line No.=10000. It cannot be zero or empty.
Error Code: TestField
ERROR CALLSTACK
37(Table 37).OnValidate(Trigger) line 12 - Base Application by Microsoft
37(Table 37).OnValidate(Trigger) line 95 - Base Application by Microsoft
ERROR OBJECT
Microsoft.Dynamics.Nav.Types.NavTestFieldException: Unit of Measure Code must have a value in Sales Line: Document Type=Invoice, Document No.=102234, Line No.=10000. It cannot be zero or empty.
at Microsoft.Dynamics.Nav.Runtime.NavRecord.TestFieldNotBlank(NCLMetaField metaField) in s:
repo
src
Platform
Server
Prod.Ncl
Runtime
NavRecord.cs:line 2601
at Microsoft.Dynamics.Nav.BusinessApplication.Record37.Unit_of_Measure_Code_a45_OnValidate_Scope.OnRun()
at Microsoft.Dynamics.Nav.Runtime.NavMethodScope.Run() in s:
repo
src
Platform
Server
Prod.Ncl
Runtime
NavMethodScope.cs:line 456
at Microsoft.Dynamics.Nav.BusinessApplication.Record37.Unit_of_Measure_Code_a45_OnValidate()
at Microsoft.Dynamics.Nav.Runtime.NavRecord.ValidateField(FieldTriggerHandler`1 fieldEvent, NCLMetaField metaField, Boolean isUserInput, List`1 beforeHandlers, List`1 afterHandlers) in s:
repo
src
Platform
Server
Prod.Ncl
Runtime
NavRecord.cs:line 697
at Microsoft.Dynamics.Nav.Runtime.NavRecord.Validate(NCLMetaField metaField, NavValue newValue, NavRecord callerRecord, Boolean isUserInput) in s:
repo
src
Platform
Server
Prod.Ncl
Runtime
NavRecord.cs:line 2958
at Microsoft.Dynamics.Nav.BusinessApplication.Record37.Noa46_a45_OnValidate_Scope.OnRun()
at Microsoft.Dynamics.Nav.Runtime.NavMethodScope.Run() in s:
repo
src
Platform
Server
Prod.Ncl
Runtime
NavMethodScope.cs:line 456
at Microsoft.Dynamics.Nav.BusinessApplication.Record37.Noa46_a45_OnValidate()
at Microsoft.Dynamics.Nav.Runtime.NavRecord.ValidateField(FieldTriggerHandler`1 fieldEvent, NCLMetaField metaField, Boolean isUserInput, List`1 beforeHandlers, List`1 afterHandlers) in s:
repo
src
Platform
Server
Prod.Ncl
Runtime
NavRecord.cs:line 697
at Microsoft.Dynamics.Nav.Runtime.NavRecord.Validate(NCLMetaField metaField, NavValue newValue, NavRecord callerRecord, Boolean isUserInput) in s:
repo
src
Platform
Server
Prod.Ncl
Runtime
NavRecord.cs:line 2958
at Microsoft.Dynamics.Nav.Service.NsDataAccess.Validate(Int32 fieldId) in s:
repo
src
Platform
Server
Prod.Service
NsDataAccess.cs:line 542
at Microsoft.Dynamics.Nav.Service.NSField.ValidateField(NavSession session) in s:
repo
src
Platform
Server
Prod.Service
NSField.cs:line 277
at Microsoft.Dynamics.Nav.Service.NSField.Validate(NavSession session) in s:
repo
src
Platform
Server
Prod.Service
NSField.cs:line 99
at SyncInvokeValidateField(Object , Object[] , Object[] )
at System.ServiceModel.Dispatcher.SyncMethodInvoker.Invoke(Object instance, Object[] inputs, Object[]& outputs)
at Microsoft.Dynamics.Nav.Service.ServiceOperationInvoker.RunInTransactionCombinator(ServiceOperation innerOperation, NSServiceBase serviceInstance, MethodBase syncMethod, Object[] inputs, Object[]& outputs) in s:
repo
src
Platform
Server
Prod.Service
ServiceOperationInvoker.cs:line 348
at Microsoft.Dynamics.Nav.Service.ServiceOperationInvoker.<>c__DisplayClass28_1.<Combine>b__1(NSServiceBase serviceInstance, Object[] inputs, Object[]& outputs) in s:
repo
src
Platform
Server
Prod.Service
ServiceOperationInvoker.cs:line 729
at Microsoft.Dynamics.Nav.Service.ServiceOperationInvoker.TransientErrorRetryCombinator(ServiceOperation innerOperation, NSServiceBase serviceInstance, MethodBase syncMethod, Object[] inputs, Object[]& outputs) in s:
repo
src
Platform
Server
Prod.Service
ServiceOperationInvoker.cs:line 369
at Microsoft.Dynamics.Nav.Service.ServiceOperationInvoker.<>c__DisplayClass28_1.<Combine>b__1(NSServiceBase serviceInstance, Object[] inputs, Object[]& outputs) in s:
repo
src
Platform
Server
Prod.Service
ServiceOperationInvoker.cs:line 729
at Microsoft.Dynamics.Nav.Service.ServiceOperationInvoker.ErrorMappingCombinator(ServiceOperation innerOperation, NSServiceBase serviceInstance, MethodBase syncMethod, Object[] inputs, Object[]& outputs) in s:
repo
src
Platform
Server
Prod.Service
ServiceOperationInvoker.cs:line 314