Import TMs to GroupShare 2017 CU10 via API fails


we have problem to import a TMs to GroupShare 2017 CU10.

we had a working program with SDL Studio 2019 (SDLTradosStudio2019_CU1_36320) - this worked

but with SDLTradosStudio2019_SR2_15.2.5.2145 its NOT. Newtosoft problem exactly like this:

any ideas if the .dlls as still not working? to me it seems that one (or more) .dll are not updated and therefor its not working.

Thanks for any HELP.