Conversion.NETFramework starting v25.12 and up, not possible to integrate in COM object

GroupDocs.Conversion Product Family
1

Hello, until version 25.11 the integration into a COM object was seamless. Since version 25.12, with the integration of the embedded fonts, using Value Tuple, it is no more possible to integrate into COM as it leads to loading issues (linked to value tuple). Can you make one release that is always COM compatible ?

2

@CyrusDaVirus

Based on your description, here is a likely technical approach for Aspose.Conversion.

The break‑age is caused by the new System.ValueTuple dependency that the 25.12 build pulls in for the embedded‑font feature; the runtime that COM loads does not automatically resolve that assembly, so the COM registration fails with a “Could not load file or assembly ‘System.ValueTuple…’” error. A quick workaround is to ship a COM‑only wrapper assembly that does not reference the font‑related code (or that removes the ValueTuple reference) and expose only the types you need via [ComVisible(true)], then register that wrapper with regasm. Alternatively, if you can target .NET Framework 4.7 or later, the ValueTuple type is baked into the framework and you can drop the external NuGet, which restores COM compatibility.

// Example wrapper (COM‑visible) without ValueTuple usage
using System.Runtime.InteropServices;

[assembly: ComVisible(true)]
namespace MyConversionComWrapper
{
    [ComVisible(true)]
    [Guid("D3A1B2C4-5E6F-7A89-0B1C-2D3E4F567890")]
    public class Converter
    {
        public string Convert(string input) => 
            ConversionLibrary.Converter.Convert(input); // call into the main lib
    }
}
  • Could you confirm the exact .NET Framework version you are building the COM object against?
  • What is the full error text you see when the COM registration or loading fails (e.g., the “Could not load file or assembly …” message)?
3

This is not a solution. Using .NET Framework 4.6.2

4

Hello @CyrusDaVirus ,

This behavior appears unusual on the side of our library. As far as I can see from the release notes for version 25.12, there were no changes related to COM objects.

I have asked our team to double-check your use case. However, to help us speed up the investigation, could you please share a small test project that reproduces the issue?

I look forward to your feedback.

5

Hello @evgen.efimov

I cannot really share much as it is when you are calling the COM object from Classic ASP (Using CreateObject). But should be reproducible from VB Script as the behavior has to be the same.

The converter class is declared with [ComVisible(true)], a ProgId and a GUID.

6

@CyrusDaVirus ,

Thank you for the clarification.
We have forwarded this information to our development team. As soon as we receive the results of their investigation, we will inform you immediately.

7

@CyrusDaVirus ,

Could you please confirm whether the System.ValueTuple library is referenced in your project?
Our developers recommend adding it, as this may resolve the issue.

If it is not currently included, please try adding it and let us know whether it helps.

8

@evgen.efimov

Yes, it gets automatically referenced when upgrading the package from 25.11 to 26.1.

9

@CyrusDaVirus ,

Alright, I will pass this information on to our development team.
I will get back to you as soon as I receive their feedback.