You're using the .NET library, right?
In one of the recent versions a breaking change was introduced, related to the default settings in the config file. You need to use an extra package. Unfortunately I forgot which.
The library maintainers refuse to document this breaking change in the change file.
Your best bet is to enter a new bug report, within a few days you should get a reply.
If you're in a hurry, look at the closed bug reports of the last six months or so.