@Mateusz Wojcik,
This error pops up from time-to-time when you start pulling in various external libraries. It comes down to a conflict between dependencies of one or more of the external libraries you're trying to use and libraries that Blue Prism is using. Starting back in v6.6, I think, Blue Prism started making heavy use of binding redirects which contributed to this.
The solution is to find a version of the 3rd party libraries that use dependent libraries (in this case System.Memory.dll) that don't conflict with what Blue Prism expects via it's binding redirects. Here's a screenshot of the Automate.exe.config from my BP v6.10.4 installation:
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You can see the reference to System.Memory.dll here and it tells you exactly what Blue Prism expects. You should also find a copy of this DLL in the Blue Prism Automate folder.
Cheers,
Eric