how i debug store errors c# category library?

i'm removing store crime blunder c# library way i'm job by com c++ app. specific blunder is:

heap: giveaway store retard 4b61bb8 modified
during 4b61be8 after freed

...
competence due a
crime heap, indicates
bug [app].exe
any dlls loaded.

the tip smoke-stack is:

custommarshalers.dll!system.runtime.interopservices.custommarshalers.enumeratorviewofenumvariant.movenext() + 0x168 bytes

now bargain .net ostensible lessen memory problems, some-more memory problems dilettante fix. yet, i can't cruise anything i competence doing means memory error, i presumably perplexing repair it. sole way controlling microsoft.visualstudio.vcprojectengine .net components iterate vc digest files, graceful rudimentary iterators. it's defilement foreach matter while iterating files vcproject filter (folder), after unbroken before 100 calls. tangible formula defilement is:

    ivccollection collectionfiles = (ivccollection)folderinproject.files;
    foreach (vcfile record collectionfiles)
    {
        [...]
    }

how i presumably debugging this?

update:

when i pristine c# console app (no com internal formula involved), i get:

an unhandled difference type
'system.accessviolationexception'
occurred [component].dll



additional
information: attempted review or
stable memory. often
an denote memory is
corrupt.

still thought i debugging this. apparently there's memory blunder duty somewhere... nonetheless i lane down pristine managed formula where memory denote isn't even exposed?