When I tried do a copy of an issue that have custom fields I get:

Server Error in '/Gemini' Application.

Cannot insert the value NULL into column 'fielddata', table 'GeminiDev.dbo.geminicustomfielddata'; column does not allow nulls. UPDATE fails. The statement has been terminated. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Data.SqlClient.SqlException: Cannot insert the value NULL into column 'fielddata', table 'GeminiDev.dbo.geminicustomfielddata'; column does not allow nulls. UPDATE fails. The statement has been terminated.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:

[SqlException (0x80131904): Cannot insert the value NULL into column 'fielddata', table 'GeminiDev.dbo.geminicustomfielddata'; column does not allow nulls. UPDATE fails. The statement has been terminated.] System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection) +1951450 System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) +4849003 System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) +194 System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj) +2394 System.Data.SqlClient.SqlDataReader.ConsumeMetaData() +33 System.Data.SqlClient.SqlDataReader.get_MetaData() +83 System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString) +297 System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async) +954 System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, DbAsyncResult result) +162 System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method) +32 System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior, String method) +141 System.Data.SqlClient.SqlCommand.ExecuteDbDataReader(CommandBehavior behavior) +12 System.Data.Common.DbCommand.System.Data.IDbCommand.ExecuteReader() +12 NHibernate.AdoNet.AbstractBatcher.ExecuteReader(IDbCommand cmd) +216 NHibernate.Id.InsertSelectDelegate.ExecuteAndExtract(IDbCommand insert, ISessionImplementor session) +52 NHibernate.Id.Insert.AbstractReturningDelegate.PerformInsert(SqlCommandInfo insertSQL, ISessionImplementor session, IBinder binder) +78

[GenericADOException: could not insert: [CounterSoft.Gemini.Commons.Entity.CustomFieldDataEN][SQL: INSERT INTO geminicustomfielddata (customfieldid, userid, projectid, issueid, fielddata) VALUES (?, ?, ?, ?, ?); select SCOPEIDENTITY()]] CounterSoft.Gemini.DataProvider.xc0186e148e957052.x9ff162179a0d4976(IssueEN x22c77d60925997e9, Int32 xdf6548ad179b4d83, Boolean xe2728ebac4544452, Boolean xc0a4df52e04990cf) +1469 CounterSoft.Gemini.Business.x95da312ae9372c2e.x9ff162179a0d4976(Int32 xdf6548ad179b4d83, Int32 x663e02d322c995c9, Int32 xa8708020b9a21a3a, IssueComponentEN[] x573dcc51157fb746, Int32 x802bdb4f457d4bbc, AffectedVersionEN[] xcd124c557aa03a42, Int32 x43c49c0b4733dd30, Boolean x046badd772a475b7, String x5b4b841715d69929, String x615b8f820cff6376, Boolean x15ee31b3727e1606) +734 CounterSoft.Gemini.Web.Issue.Windows.CopyIssue.btnCopy_Click(Object sender, EventArgs e) +479 System.Web.UI.WebControls.Button.OnClick(EventArgs e) +111 System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +110 System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +10 System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +13 System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +36 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1565

Version Information: Microsoft .NET Framework Version:2.0.50727.4927; ASP.NET Version:2.0.50727.4927