Cannot read the next data row for dataset (rsErrorReadingNextDataRow)

I have a report which runs fine on Visual Studio. But when I run from report server, I get below error:

• An
  error has occurred during report processing. (rsProcessingAborted)
  
  • Cannot
    read the next data row for the dataset Enrolments.
    (rsErrorReadingNextDataRow)
    
    • For
      more information about this error navigate to the report server on the local
      server machine, or enable remote errors

    Enrolments:

    SELECT DISTINCT CAST(e.College_Year AS VARCHAR(10)) AS ClgYear,
            e.Code,
            e.Title,
            e.Coordinator_Code,
            e.Coordinator_Forename,
            e.Coordinator_Surname,
            st.Learner_ID,
            st.Surname,
           st.Forename_1,
           st.Age,
           case when st.Gender = 'Female' then 'F'
                else 'M'
           end as Gender,
           case when st.English_1St_Lang = '1' then 'Yes'
                else 'No'
           end as Eng_1st_Lang,
           st.Ethnicity,
           qe.QoE_Grade as GCSE_English,
          qm.QoE_Grade as GCSE_Maths,
           sc.Forename_1 + ' ' +sc.Surname as ParentName,
           '' as Email,
           sc.Home_Telephone_No as ParentHomeTelephone,
           sc.Mobile_Telephone_NO as ParentMobileTelephone,

    case when df.STLD_Student_ID is not null then 'Y' else 'N' end as Learner_Difficulty_YN,
    -----------------------------------------------------
    ----st.Learning_Difficulty,
    -----------------------------------------------------
    case when ds.STLD_Student_ID is not null then 'Y' else 'N' END AS Disability_YN
           --st.Learning_Difficulty + ' - ' + st.Disability as [Learning Difficulty Disability]
    ,Class_Code
    ,e.Qualification_Mgmnt_Code_1
    ,e.Qualification_Department
    ,Qualification_Mgmnt_Code_2
    ,Qualification_Section
    ,st.Photo_File_Name
          
    --CASE WHEN Completion_Stat_Q19 = 1 THEN 'Continuing'
    --     WHEN Completion_Stat_Q19 = 2 THEN 'Completed'
    --     WHEN Completion_Stat_Q19 = 3 THEN 'Withdrawn'
    --      WHEN Completion_Stat_Q19 = 4 THEN 'Transferred'
    --END AS Completion_Stat

    FROM    dbo.IM_EN_Enrolments_vw e JOIN
            dbo.IM_ST_Students_vw st ON
            CAST(e.College_Year AS VARCHAR(10)) = CAST(st.College_Year AS VARCHAR(10))
       AND e.Learner_ID = st.Learner_ID
      
       left join
         dbo.IM_ST_Student_Contacts_vw as sc on
         st.Learner_ID = sc.Learner_ID
         ------------------------------------
         and sc.Emergency_Priority = '1'
         ------------------------------------

    left join dbo.IM_QoE_EnglishLang_GCSE_vw qe on st.Learner_ID = qe.Learner_ID
      left join dbo.IM_QoE_MathsGCSE_vw qm on st.Learner_ID = qm.Learner_ID
    left join dbo.STLDLearnerLLDD df on df.STLD_Student_ID = st.Learner_ID and
    CAST(df.STLD_Year AS VARCHAR(10)) = CAST(e.College_Year AS VARCHAR(10))and df.STLD_LLDDCode IN ('8','10','11','12','13','14','15','94','96')
    left join dbo.STLDLearnerLLDD ds on ds.STLD_Student_ID = st.Learner_ID
    and CAST(ds.STLD_Year AS VARCHAR(10))  = CAST(e.College_Year AS VARCHAR(10)) and ds.STLD_LLDDCode IN ('4','5','6','7','9','16','93','95','97')
    WHERE CAST(e.College_Year AS VARCHAR(10)) =@College_Year -- '2013'
    AND Qualification_Mgmnt_Code_2 = @QualSection
    AND e.Code = @Qualification_Code --'12621/F11' 
    and CAST(e.College_Year AS VARCHAR(10))> '2012'

    AND Start_date <> isnull(Actual_End_Date, '01-Aug-2020')

    ORDER BY  st.Surname, st.Learner_ID

    Any help is much appreciated.

    Thanks.

    Ar