NHibernate - ResetParametersIndexesForTheCommand Heap Corruption

does anyone have ANY idea what might be causing this?

this line in NHibernate is causing the application to crash.

if (effectiveParameterLocations.Length > 0) // Parameters previously present

my only guess is that effectiveParameterLocations doesn't have a Length attribute somehow.

the application is a web app, NHibernate successfully connects to the database to get one set of objects from one table going through this very code, whilst setting up the query for the next set of objects it crashes.

public void ResetParametersIndexesForTheCommand(int singleSqlParametersOffset)
    {
        // a better place could be the Bind of each IParameterSpecification but we have to do it before bind values
        // in this way the same parameter of a dynamic-filter will be set with two different parameter-names in the same command (when it is a command-set). 
        if (singleSqlParametersOffset < 0)
        {
            throw new AssertionFailure("singleSqlParametersOffset < 0 - this indicate a bug in NHibernate ");
        }
        // due to IType.NullSafeSet(System.Data.IDbCommand , object, int, ISessionImplementor) the SqlType[] is supposed to be in a certain sequence.
        // this mean that found the first location of a parameter for the IType span, the others are in secuence
        foreach (IParameterSpecification specification in Specifications)
        {
            string firstParameterId = specification.GetIdsForBackTrack(factory).First();
            int[] effectiveParameterLocations = SqlQueryParametersList.GetEffectiveParameterLocations(firstParameterId).ToArray();

         if (effectiveParameterLocations.Length > 0) // Parameters previously present might have been removed from the SQL at a later point.
            {
                int firstParamNameIndex = effectiveParameterLocations.First() + singleSqlParametersOffset;
                foreach (int location in effectiveParameterLocations)
                {
                    int parameterSpan = specification.ExpectedType.GetColumnSpan(factory);
                    for (int j = 0; j < parameterSpan; j++)
                    {
                        sqlQueryParametersList[location + j].ParameterPosition = firstParamNameIndex + j;
                    }
                }
            }
        }
    }

I believe it to be that line because of DILE –

.method public hidebysig final virtual newslot instance void 
ResetParametersIndexesForTheCommand(int32 singleSqlParametersOffset) cil managed 
{
//Code size 229 (0xe5)
//Token: 0x0600440a
.maxstack 16
.locals init (class [mscorlib]System.Collections.Generic.IEnumerator`1<class NHibernate.Param.IParameterSpecification> V_0,
  class NHibernate.Param.IParameterSpecification V_1,
  string V_2,
  int32[] V_3,
  int32 V_4,
  int32[] V_5,
  int32 V_6,
  int32 V_7,
  int32 V_8,
  int32 V_9)
ldarg.1
ldc.i4.0
bge IL_0012
ldstr "singleSqlParametersOffset < 0 - this indicate a bug in NHibernate "
newobj instance void NHibernate.AssertionFailure::.ctor(string)
throw
ldarg.0
call instance class [mscorlib]System.Collections.Generic.IEnumerable`1<class NHibernate.Param.IParameterSpecification> NHibernate.SqlCommand.SqlCommandImpl::get_Specifications()
callvirt instance class [mscorlib]System.Collections.Generic.IEnumerator`1<!0> class [mscorlib]System.Collections.Generic.IEnumerable`1<class NHibernate.Param.IParameterSpecification>::GetEnumerator()
stloc.0
.try
{
    br IL_00c7
    ldloc.0
    callvirt instance !0 class [mscorlib]System.Collections.Generic.IEnumerator`1<class NHibernate.Param.IParameterSpecification>::get_Current()
    stloc.1
    ldloc.1
    ldarg.0
    ldfld class NHibernate.Engine.ISessionFactoryImplementor NHibernate.SqlCommand.SqlCommandImpl::factory
    callvirt instance class [mscorlib]System.Collections.Generic.IEnumerable`1<string> NHibernate.Param.IParameterSpecification::GetIdsForBackTrack(class NHibernate.Engine.IMapping)
    call !!0 [System.Core]System.Linq.Enumerable::First<string>(class [mscorlib]System.Collections.Generic.IEnumerable`1<!!0>)
    stloc.2
    ldarg.0
    call instance class [mscorlib]System.Collections.Generic.List`1<class NHibernate.SqlCommand.Parameter> NHibernate.SqlCommand.SqlCommandImpl::get_SqlQueryParametersList()
    ldloc.2
    call class [mscorlib]System.Collections.Generic.IEnumerable`1<int32> NHibernate.Param.ParametersBackTrackExtensions::GetEffectiveParameterLocations(class [mscorlib]System.Collections.Generic.IList`1<class NHibernate.SqlCommand.Parameter>, string)
    call !!0[] [System.Core]System.Linq.Enumerable::ToArray<int32>(class [mscorlib]System.Collections.Generic.IEnumerable`1<!!0>)
    stloc.3
    ldloc.3
    ldlen
    conv.i4
    ldc.i4.0
    ble IL_00c7
    ldloc.3                          KAABBOOOOOOOMMMM!!!!
    call !!0 [System.Core]System.Linq.Enumerable::First<int32>(class [mscorlib]System.Collections.Generic.IEnumerable`1<!!0>)
    ldarg.1
    add
    stloc.s V_4
    ldloc.3                            
    stloc.s V_5
    ldc.i4.0
    stloc.s V_6
    br IL_00bf
    ldloc.s V_5
    ldloc.s V_6
    ldelem.i4
    stloc.s V_7
    ldloc.1
    callvirt instance class NHibernate.Type.IType NHibernate.Param.IParameterSpecification::get_ExpectedType()
    ldarg.0
    ldfld class NHibernate.Engine.ISessionFactoryImplementor NHibernate.SqlCommand.SqlCommandImpl::factory
    callvirt instance int32 NHibernate.Type.IType::GetColumnSpan(class NHibernate.Engine.IMapping)
    stloc.s V_8
    ldc.i4.0
    stloc.s V_9
    br IL_00b3
    ldarg.0
    ldfld class [mscorlib]System.Collections.Generic.List`1<class NHibernate.SqlCommand.Parameter> NHibernate.SqlCommand.SqlCommandImpl::sqlQueryParametersList
    ldloc.s V_7
    ldloc.s V_9
    add
    callvirt instance !0 class [mscorlib]System.Collections.Generic.List`1<class NHibernate.SqlCommand.Parameter>::get_Item(int32)
    ldloc.s V_4
    ldloc.s V_9
    add
    newobj instance void valuetype [mscorlib]System.Nullable`1<int32>::.ctor(!0)
    callvirt instance void NHibernate.SqlCommand.Parameter::set_ParameterPosition(valuetype [mscorlib]System.Nullable`1<int32>)
    ldloc.s V_9
    ldc.i4.1
    add
    stloc.s V_9
    ldloc.s V_9
    ldloc.s V_8
    blt.s IL_008e
    ldloc.s V_6
    ldc.i4.1
    add
    stloc.s V_6
    ldloc.s V_6
    ldloc.s V_5
    ldlen
    conv.i4
    blt.s IL_006c
   ldloc.0
    callvirt instance bool [mscorlib]System.Collections.IEnumerator::MoveNext()
    brtrue IL_0023
    leave IL_00e4
} //end try
finally
{
    ldloc.0
    brfalse IL_00e3
    ldloc.0
    callvirt instance void [mscorlib]System.IDisposable::Dispose()
    endfinally
} //end finally
ret
} //end of method NHibernate.SqlCommand.SqlCommandImpl::ResetParametersIndexesForTheCommand

Stepping on at the KABOOM line simply exits the thread with an unhandled heap corruption error –

Faulting application name: w3wp.exe, version: 7.5.7601.17514, time stamp: 0x4ce7a5f8
Faulting module name: ntdll.dll, version: 6.1.7601.23677, time stamp: 0x589c957a
Exception code: 0xc0000374
Fault offset: 0x000ce8fb
Faulting process id: 0x1c50
Faulting application start time: 0x01d2c36a0e8b882e
Faulting application path: C:\Windows\SysWOW64\inetsrv\w3wp.exe
Faulting module path: C:\Windows\SysWOW64\ntdll.dll
Report Id: 50a95bb0-2f5e-11e7-9e4f-0050569641a1

the table in question that the objects are populated from looks normal, and has half a dozen columns all simple stuff, standard poco.

the generated query has 1 parameter.

the query from right before the explosion -

SELECT this_.Id as Id25_0_, this_.Source_Name as Source2_25_0_, this_.Description as Descript3_25_0_, this_.Enabled as Enabled25_0_, this_.Last_Updated_Time as Last5_25_0_, this_.Last_Updated_User as Last6_25_0_, this_.Class_Property_Name as Class7_25_0_ FROM Template_Fields_Profile this_ WHERE this_.Enabled = 1 and this_.Class_Property_Name is not null

thanks