When trying to add, edit, or import licenses via Web UI or Snow Management and Configuration Center (SMACC) the action fails and the following error is logged: 

System.Data.SqlClient.SqlException (0x80131904): When converting an nvarchar data type to a datetime data type, the value is out of range.  The statement has ended.

The System locale is set to German and the database collation is set to default. Changing language settings in the UI does not have an impact on the success. 

Imports from the same excel file are successful on other systems. 

Adding the license

Logs:

Editing a license

Unable to edit the license imported via Web Configurator

Logs: 

Import via Web Configurator works: 

Import via SMACC - It indicated that two rows imported but nothing imported in the database, so nothing displayed in Web UI, License:

Logs: 

[ERR] (SnowSoftware.LicenseManager.Imports.EventHandlers.CommandHandlers.ValidateCommandRequestHandler) Bei der Konvertierung eines nvarchar-Datentyps in einen datetime-Datentyp liegt der Wert außerhalb des gültigen Bereichs.
System.Data.SqlClient.SqlException (0x80131904): Bei der Konvertierung eines nvarchar-Datentyps in einen datetime-Datentyp liegt der Wert außerhalb des gültigen Bereichs.
  at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction)
  at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction)
  at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose)
  at System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady)
  at System.Data.SqlClient.SqlDataReader.TryHasMoreRows(Boolean& moreRows)
  at System.Data.SqlClient.SqlDataReader.TryReadInternal(Boolean setTimeout, Boolean& more)
  at System.Data.SqlClient.SqlDataReader.Read()
  at Dapper.SqlMapper.QueryImpl[T](IDbConnection cnn, CommandDefinition command, Type effectiveType)+MoveNext() in C:\projects\dapper\Dapper\SqlMapper.cs:line 1096
  at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
  at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
  at Dapper.SqlMapper.Query[T](IDbConnection cnn, String sql, Object param, IDbTransaction transaction, Boolean buffered, Nullable`1 commandTimeout, Nullable`1 commandType) in C:\projects\dapper\Dapper\SqlMapper.cs:line 721
  at SnowSoftware.LicenseManager.Imports.DataAccess.UnitOfWork.UnitOfWork.Get[T](String sql)
  at SnowSoftware.LicenseManager.Imports.DataAccess.Repositories.AgreementRepository.GetAgreementsByValidityDate(Int32 tenantId, DateTime date)
  at SnowSoftware.LicenseManager.Imports.Domain.FieldValidators.PurchaseDateValidator.<>c__DisplayClass2_0.<Validate>b__0(ColumnValidationBagAndValueCarrier _)
  at SnowSoftware.LicenseManager.Imports.Domain.FieldValidators.ExistsValueValidator.Validate(ColumnValidationBag validationBag, Object value)
  at SnowSoftware.LicenseManager.Imports.Domain.FieldValidators.PurchaseDateValidator.Validate(ColumnValidationBag validationBag, Object value)
  at SnowSoftware.LicenseManager.Imports.Domain.Extensions.ColumnExtensions.Validate(Column column, ImportCell cellValue, ColumnValidationBag validationBag)
  at SnowSoftware.LicenseManager.Imports.Domain.LicenseImport.LicenseImport.ValidateColumn(Column column, ImportCell dataCell, ImportRow importRow, Dictionary`2 globalValueStash)
  at SnowSoftware.LicenseManager.Imports.Domain.LicenseImport.LicenseImport.ValidateRowAndColumns(ImportRow dataRow)
  at SnowSoftware.LicenseManager.Imports.Domain.LicenseImport.LicenseImport.ValidateAllRows()
  at SnowSoftware.LicenseManager.Imports.Domain.LicenseImportManager.ExecuteValidationAsync(Int32 tenantId, Int32 userId, Guid importId)
  at SnowSoftware.LicenseManager.Imports.Domain.LicenseImportManager.ExecuteValidationAsync(Int32 tenantId, Int32 userId, Guid importId)
  at SnowSoftware.LicenseManager.Imports.EventHandlers.CommandHandlers.ValidateCommandRequestHandler.Handle(ValidateCommandRequestEvent validateRequest)
ClientConnectionId:391c7f84-09ef-46bd-9482-2898b7b0e048
Error Number:242,State:3,Class:16
2021-12-02 11:12:17.096 +01:00 [INF] (SnowSoftware.LicenseManager.Imports.EventHandlers.CommandHandlers.ValidateCommandRequestHandler) ValidateCommandResponseEvent has been successfully sent. SnowSoftware.LicenseManager.Imports.Messages.External.Events.ValidateCommandRequestEvent

9.16.2 / 9.18.0

1.    Login to the Microsoft SQL Management Studio

2.    On the left panel side, go to Security -> Logins then select LicenseManagerUser

3.    Right-click LicenseManagerUser then click Properties

4.    Check Snow License Manager database, and ensure that the language is set to English. 

Language setting of LicenseManagerUser was set to German and setting that to English resolved the issue