Unable to load custom visualizer of LLBL Gen Pro in VS19


I am using Visual Studio 2019. To C:\Users...\Documents\Visual Studio 2019\Visualizers I have added the following dll files to enable a visualizer for predicate buckets by LLBL Gen Pro. This approach works for VS 2017.

The dll files: SD.LLBLGen.Pro.DebugVisualizers2017.dll, SD.LLBLGen.Pro.DQE.SqlServer.dll, SD.LLBLGen.Pro.ORMSupportClasses.dll

When trying to use it in VS19, I get the following error prompt:

Unable to load the custom visualizer. Could not load file or assembly 'SD.LLBLGen.Pro.DebugVisualizers2017, Version=, Culture=neutral, PublicKeyToken=ca73b74ba4e3ff27' or one of its dependencies. Operation is not supported. (Exception from HRESULT: 0x80131515)

Has anyone encountered this problem before? What could I do about it?

The code snippet where I am trying to observe/ visualize the predicate:

     class Something {

     public void DoSG(TransactionListFilters filters)  

          var transactionBucket = GetTransactionBucket(filters);
          var locationBucket = GetTransactionBucket(filters, false, true); }

asked on Stack Overflow Aug 2, 2019 by Csanád • edited Aug 2, 2019 by Panagiotis Kanavos

1 Answer


The debugger visualizers are compiled against the visualizer dll for the particular vs version. For vs 2019 we ship a visualizer in v5.6 which is currently in beta.

ps: next time, ask the question on our support forums as we don't actively monitor stack overflow. https://www.llblgen.com/tinyforum.

If you want to have the visualizer be compiled against the dll from vs 2019, use the sourcecode for the runtimes, which is available to you on our website after you've logged in (under the extras section for downloads for a particular version).

answered on Stack Overflow Aug 2, 2019 by Frans Bouma

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