Hi Raimo, this looks like a conflict between the intreop file and the installed MultiTerm COM classes. Which interop file are you referencing in your project? Also keep in mind that MultiTerm and Studio use the same shared terminology components. A common cause for trouble. Let's assume you have installed MultiTerm 2021 SR1, and linked C:\Program Files (x86)\Common Files\Trados\MultiTerm16\Sdl.MultiTerm.TMO.Interop.dll. If you now install Studio 2021 SR2, you'll likely get the class not registered error. This can get ugly, especially if you installed many different versions on a machine, or for extra fun had a crash during un/installation.

So the first steps I'd look at:

• check there is only one version of MultiTerm and Studio installed
• check that they are both on the same version. The release note usually contain information on compatible releases
• check that the interop dll is from the same version

Cheers, Gerhard

Hello Gerhard,

sorry for the late response but I was working on a bunch of high priority projects and did not get time allotted to test your solution until now. Sadly I had no success. We even set up a completely new test environment but had no success getting the sample project running there either with the same error at the exact same line in our code.

Do you have any other theories on what could be the issue we're facing? Were you able to reproduce our issue?

Thank you in advance for any further assistance you can provide.

Kind regards

Raimo Geisel

Tagging Gerhard Kordmann  - thanks

I can easily reproduce this error by using a Sdl.MultiTerm.TMO.Interop.dll that is from a different version. The interop is basically a map between class names and UIDs. When the code asks to create a Tmo.Interop.Application object, the frameworks loads the UID for "Application" from the interop and then goes looking for it in the registry CLSID list. If it finds it, that is enough to create a COM object. If it doesn't find it, you get the "Class not registered" error.

To allow side by side installations of different versions, the UIDs change for each major Trados version

On your screen shot, the missing UID is {DE9895DD-A527...} which is the code from Trados 2019. So it looks like your project is referencing an old interop file from Trados 2019. That also explains why reinstallations of 2021 and 2022 did not work. So I can just advise that you check again which interop the project uses, and point it to a new one from your current installation of Trados. Library versioning and side by side installations are a pain the neck. 

Good luck, Gerhard

I can easily reproduce this error by using a Sdl.MultiTerm.TMO.Interop.dll that is from a different version. The interop is basically a map between class names and UIDs. When the code asks to create a Tmo.Interop.Application object, the frameworks loads the UID for "Application" from the interop and then goes looking for it in the registry CLSID list. If it finds it, that is enough to create a COM object. If it doesn't find it, you get the "Class not registered" error.

To allow side by side installations of different versions, the UIDs change for each major Trados version

On your screen shot, the missing UID is {DE9895DD-A527...} which is the code from Trados 2019. So it looks like your project is referencing an old interop file from Trados 2019. That also explains why reinstallations of 2021 and 2022 did not work. So I can just advise that you check again which interop the project uses, and point it to a new one from your current installation of Trados. Library versioning and side by side installations are a pain the neck. 

Good luck, Gerhard

Hi Gerhard,

so if I understand you correctly it is impossible for us to support more than one specific MultiTerm Version at the same time without providing multiple setups, each with a different interop, correct?

That seems like an issue as we can not control which version of MultiTerm each of our customers uses. Sometimes they even rotate licenses of older versions to junior staff while senior staff get the yearly update to keep down cost.

Kind regards

Raimo Geisel

So, I just tested it really quickly and it did not work either, using MultiTerm 2021 SR2 V 16.2.10.9305 with the TMO.Interop from this versions install path with V 16.2.1.1044.

Hi Raimo,

that's right, by default, a build is for one release only. That's why most apps offer multiple release specific versions. It's possible to hack your way around it - the glossary converter has one file for all versions - but it's not pretty 

exact same error, with DE9895DD-A527... ? Then it still seems to cling on to a wrong mttmo somehow. Visual Studio can be creative in searching dependencies. The sample project you mention in the first post comes with this weird hint path, for example:

<Reference Include="Sdl.MultiTerm.TMO.Interop">
<HintPath>$(MSBuildProgramFiles32)\SDL\SDL Trados Studio\Studio16\Sdl.MultiTerm.TMO.Interop.dll</HintPath>
<EmbedInteropTypes>True</EmbedInteropTypes>
</Reference>