Thank you Aaron ,

But I have more questions

1-It worked when using 'sa' user, but in production I'm using another user  and I get the first error message.

ERROR [42000] [Microsoft][SQL Native Client][SQL Server]User does not have permission to perform this action.

2-I need to know what permissions should be with the SQL user?

3-Should I let "Flestream" enabled or I can disable it after configuration?

Thanks

No problem.

Not sure if you saw this one as well. Maybe it will help?

https://www.laserfiche.com/support/webhelp/Laserfiche/10/en-us/administration/#../Subsystems/discussions/Content/ConfigDatabase.htm%3FTocPath%3DDiscussions%7CInstalling%2520and%2520Configuring%2520the%2520Laserfiche%2520Discussions%2520Server%7C_____3

I would imagine that Filestream is a requirement for discussions to work correctly even after installation. Maybe someone from Laserfiche is able to answer your other questions.

After applying required permissions and rules , I get another error 

In event viewer I get these errors also

Message: System.Data.Odbc.OdbcException (0x80131937): ERROR [42S02] [Microsoft][SQL Native Client][SQL Server]Invalid object name 'LFDiscussionsDBTest.dbo.Options'.
   at System.Data.Odbc.OdbcConnection.HandleError(OdbcHandle hrHandle, RetCode retcode)
   at System.Data.Odbc.OdbcCommand.ExecuteReaderObject(CommandBehavior behavior, String method, Boolean needReader, Object[] methodArguments, SQL_API odbcApiMethod)
   at System.Data.Odbc.OdbcCommand.ExecuteReaderObject(CommandBehavior behavior, String method, Boolean needReader)
   at System.Data.Odbc.OdbcCommand.ExecuteReader(CommandBehavior behavior)
   at Laserfiche.Answers.AnswersConfig.Infrastructure.DatabaseHelper.AnswersSchemaExists(OdbcConnection conn)

Title:
Category: General
EventId: 100
Machine: NEW-LFWTEST
App Domain: /LM/W3SVC/1/ROOT/DiscussionsConfig-1-131649807411366165
ProcessId: 5020
Process Name: c:\windows\system32\inetsrv\w3wp.exe
Thread Name: 
Win32 ThreadId:7252
Extended Properties: 

Message: System.ArgumentException: The path is not of a legal form.
   at System.IO.Path.NormalizePath(String path, Boolean fullCheck, Int32 maxPathLength, Boolean expandShortPaths)
   at System.IO.Path.GetDirectoryName(String path)
   at Laserfiche.Answers.AnswersConfig.Infrastructure.DatabaseHelper.CreateDB(OdbcConnection conn, Boolean createDB, String schemaFolder)
   at Laserfiche.Answers.AnswersConfig.Infrastructure.DatabaseInfo.SaveDatabseInfo()
   at Laserfiche.Answers.AnswersConfig.Controllers.ConfigurationController.SetDatabaseInfo(DatabaseInfo databaseInfo)
   at lambda_method(Closure , ControllerBase , Object[] )
   at System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters)
   at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters)
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.<BeginInvokeSynchronousActionMethod>b__39(IAsyncResult asyncResult, ActionInvocation innerInvokeState)
   at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResult`2.CallEndDelegate(IAsyncResult asyncResult)
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult)
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3d()
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<>c__DisplayClass46.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3f()
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethodWithFilters(IAsyncResult asyncResult)
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass21.<>c__DisplayClass2b.<BeginInvokeAction>b__1c()
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass21.<BeginInvokeAction>b__1e(IAsyncResult asyncResult)
Exception Data:
Url: /DiscussionsConfig/configuration/setdatabaseinfo
Method: POST
User: NEW-LFWTEST\Administrator
Headers: Connection=keep-alive&Content-Length=166&Content-Type=application%2fjson%3b+charset%3dUTF-8&Accept=application%2fjson%2c+text%2fjavascript%2c+*%2f*%3b+q%3d0.01&Accept-Encoding=gzip%2c+deflate%2c+br&Accept-Language=en%2cen-US%3bq%3d0.9%2car%3bq%3d0.8&Cookie=ASP.NET_SessionId%3d1du505z41n2xqajthqy2fa5k&Host=localhost&Referer=http%3a%2f%2flocalhost%2fDiscussionsConfig&User-Agent=Mozilla%2f5.0+(Windows+NT+6.1%3b+Win64%3b+x64)+AppleWebKit%2f537.36+(KHTML%2c+like+Gecko)+Chrome%2f65.0.3325.146+Safari%2f537.36&Origin=http%3a%2f%2flocalhost&X-Requested-With=XMLHttpRequest


Title:
Category: General
EventId: 100
Machine: NEW-LFWTEST
App Domain: /LM/W3SVC/1/ROOT/DiscussionsConfig-1-131649807411366165
ProcessId: 5020
Process Name: c:\windows\system32\inetsrv\w3wp.exe
Thread Name: 
Win32 ThreadId:7252
Extended Properties: