Ah. Well, at least now it's only affecting the thing that should actually be using it.
This looks to me like a combination of package management failing and the feature not actually being ready. I went to Nuget and downloaded that DLL, dropped it in the program folder, and restarted the client, and it gave me a similar error indicating it was looking for a different version of Google.Protobuf from the one provided. Rinse and repeat, missing Google.Api.Gax.Grpc. Rinse and repeat again...and the error is now "Could not find file 'C:\Program Files (x86)\VisualCron\JSONPath'. on string:..."
Give it a filename that exists, and it complains about either finding a null (if the file is empty) or the first character being unexpected (for the handful of things I tried), but...I can't fathom why it's looking for a file for this in the first place, let alone guess what it expects to find in it.
Plus, "[FEATURE] Client/Server: Translation->Added translation to many languages (VC-2050)" appears in the changes so far for the current beta, and notably not in any recent changelogs for released versions.
I think maybe a partially-completed feature was released by accident in a non-working state. And the issue in 9.9.0 might have been that the assembly reference was mistakenly added in almost all the variable code paths, instead of only the one where it was going to be used. Hard to say for sure.