Need help with general LS 3 Exception on join

Hi, trying to implement JOINs in our solution, but for first query usage I keep getting Mindscape.LightSpeed.LightSpeedException with not much details. It's also my first real exploration of LINQ joins, possibly doing something wrong. But not sure how to get more details and proceed.

I've tested LS join with small two-table example and this looks fine. What I am trying to implement in acutal solution is more complex with 4 joins. It's friday afternoon, so no real time to get sample project, but actually probably is an understandable example (UserManagement - users, roles and rights), so here's the code:
-----
var queryModules = from right in uow.UserRightLookups
                   join rightRole in uow.UserRightForRoles on right.Id equals rightRole.UserRightId
                   join role in uow.UserRoles on rightRole.UserRoleId equals role.Id
                   join roleUser in uow.UserRoleForUsers on role.Id equals roleUser.UserRoleId
                   join user in uow.Users on roleUser.UserId equals user.Id
                   where user.Username == userName
                   select right.ApplicationModuleId;
List<int> assignedModulesId = queryModules.Distinct().ToList();
-------

LightSpeedException thrown at ToList with stack trace:
--------
   at Mindscape.LightSpeed.Querying.Selectable.TypeSelectable.(IUnitOfWork , String , String )
   at Mindscape.LightSpeed.Querying.Join.(IUnitOfWork , EntityMap )
   at ..(AliasedTypeModel )
   at ..(LightSpeedContext , List`1 , QueryExpression , Order , Group , String , Boolean , Boolean )
   at ..(List`1 , Query , String , IdentifierBLOCKED EXPRESSION
   at ..(List`1 , Query )
   at ..(List`1 , Query , EntityTuple )
   at ..(UnitOfWorkBase , List`1 , Query , EntityTuple )
   at ..(Query , List`1 , EntityTuple )
   at ..(Query , EntityTuple )
   at Mindscape.LightSpeed.UnitOfWork.FindGroup(Query query, EntityTuple results)
   at Mindscape.LightSpeed.UnitOfWorkBase.Find(Query query, EntityMap typeMap)
   at Mindscape.LightSpeed.Linq.Plan.SingleQueryPlan.ExecuteImmediate(IUnitOfWork unitOfWork, Type returnType)
   at Mindscape.LightSpeed.Linq.LinqQueryProvider.Execute(Expression expression)
   at Mindscape.LightSpeed.Linq.LinqQueryProvider.System.Linq.IQueryProvider.Execute(Expression expression)
   at Mindscape.LightSpeed.Linq.LinqQuery`1.GetEnumerator()
   at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
   at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)

Thanks for reporting this.  It will be fixed in the next drop.

Thanks Ivan, I've tried the fix. The exception is gone. However, I do have doubts regarding the generated SQL.

The query from first post is generating this SQL:
SELECT
...
FROM
  ADM_USER_RIGHT_LOOKUP t0
  CROSS JOIN
  ADM_USER t4
  CROSS JOIN
  ADM_USER_ROLE t2
  CROSS JOIN
  ADM_USER_ROLE_FOR_USER t3
INNER JOIN
  ADM_USER_RIGHT_FOR_ROLE t1
ON
  t0.Id = t1.USER_RIGHT_ID
WHERE
  t4.Username = :p0;
 

Almost all are cross joins, although LINQ query has all inner joins.
Also, select part is selecting all columns from all tables, not just one column as specified in LINQ query.


I also pushed the limits a bit further and added a group by to inital query (query modified at the end):
var queryModules = from right in uow.UserRightLookups
                   join rightRole in uow.UserRightForRoles on right.Id equals rightRole.UserRightId
                   join role in uow.UserRoles on rightRole.UserRoleId equals role.Id
                   join roleUser in uow.UserRoleForUsers on role.Id equals roleUser.UserRoleId
                   join user in uow.Users on roleUser.UserId equals user.Id
                   where user.Username == userName
                   group right by right.ApplicationModuleId into g
                   select g.Key;

The SQL generated from this query is invalid (see after table t4, cross joins are repeating):
SELECT
  t1."APPLICATION_MODULE_ID_"
FROM
  (
    SELECT DISTINCT
      t0.APPLICATION_MODULE_ID AS "APPLICATION_MODULE_ID_"
    FROM
      ADM_USER_RIGHT_LOOKUP
      CROSS JOIN
      ADM_USER_ROLE t2
      CROSS JOIN
      ADM_USER_ROLE_FOR_USER t3
      CROSS JOIN
      ADM_USER t4
    GROUP BY
      t0.APPLICATION_MODULE_ID
  CROSS JOIN
  ADM_USER_ROLE t2
  CROSS JOIN
  ADM_USER_ROLE_FOR_USER t3
  CROSS JOIN
  ADM_USER t4
  )
  t1
INNER JOIN
  ADM_USER_RIGHT_FOR_ROLE t1
ON
  t0.Id = t1.USER_RIGHT_ID
WHERE
  EXISTS (
    SELECT
      *
    FROM
      ADM_USER_RIGHT_LOOKUP
      CROSS JOIN
      ADM_USER t4
    WHERE
      t4.Username = :p0 AND
      t0.APPLICATION_MODULE_ID = t1."APPLICATION_MODULE_ID_"
  );


The two sub-selects parts here are also not sensible to me. Note that with group by, select part look like is properly generated (only selecting one column).