Error in 10.1 admin

Hi,

I have a BPC 10.1 MS installation on a virtual server with Windows 2008 R2 Enterprise OS and SQL 2008 R2 as the database. Whenever I try to change or add a remark in a business rule I get an error message:

It makes no difference which rule or which environment, it happens in all.

I had a look at the Log table in SQL and got this:

LogID SystemName JobName UserID Status DateWritten Message 800 ApplicationService OSoft.Services.Webservice.ApplicationService.ApplicationService.Query() BPC10VM\Administrator 0 2015-07-15 09:34:02.787   ==============[System Error Tracing]==============  [System  Name] : ApplicationService  [Message Type] : ErrorMessage  [Job Name]    : OSoft.Services.Webservice.ApplicationService.ApplicationService.Query()  [DateTime]    : 07/15/2015 09:34:02  [UserId]      : BPC10VM\Administrator  [Exception]      DetailMsg  : {System.NullReferenceException: Object reference not set to an instance of an object.    at Microsoft.VisualBasic.CompilerServices.Symbols.Container.InvokeMethod(Method TargetProcedure, Object[] Arguments, Boolean[] CopyBack, BindingFlags Flags)    at Microsoft.VisualBasic.CompilerServices.NewLateBinding.ObjectLateGet(Object Instance, Type Type, String MemberName, Object[] Arguments, String[] ArgumentNames, Type[] TypeArguments, Boolean[] CopyBack)    at OSoft.Services.Webservice.RuleService.RuleService.UpdateRules(String strParameter, String strContext)}  ==============[System Error Tracing  End ]==============

LogID SystemName JobName UserID Status DateWritten Message 799 OSoftCustomXMLSvr XMLCreator::ConvertDataSetToXmlString 0 2015-07-15 09:34:02.777   ==============[System Error Tracing]==============  [System  Name] : OSoftCustomXMLSvr  [Message Type] : ErrorMessage  [Job Name]    : XMLCreator::ConvertDataSetToXmlString  [DateTime]    : 07/15/2015 09:34:02  [UserId]      :  [Exception]      DetailMsg  : {System.NullReferenceException: Object reference not set to an instance of an object.    at OSoft.Services.Application.CustomXMLSvr.CustomXML.XMLCreator.ConvertDataSetToXmlString(DataSet ds)}  ==============[System Error Tracing  End ]==============

LogID SystemName JobName UserID Status DateWritten Message 798 OSoftRuleManage InsertNewCurrencyConversion() OSoftRuleManage 0 2015-07-15 09:34:02.767   ==============[System Error Tracing]==============  [System  Name] : OSoftRuleManage  [Message Type] : ErrorMessage  [Job Name]    : InsertNewCurrencyConversion()  [DateTime]    : 07/15/2015 09:34:02  [UserId]      : OSoftRuleManage  [Exception]      DetailMsg  : {System.NullReferenceException: Object reference not set to an instance of an object.    at OSoft.Services.Application.RuleManage.Handler.InsertNewCurrencyConversionHeader(String strAppsetName, String strTableName, String strApplicationName, DataSet ds, String strFilterName, String strDeletedHeaders)}  ==============[System Error Tracing  End ]==============

Would anyone have any idea how to solve this??

Thanks
Arnold