Thanks for the report and the stack trace, and sorry about this. 2.10.0 called a class before the file that defines it was loaded, which caused a fatal error on every request, not only in WP-CLI. It’s fixed in 2.10.1, which is out now: wp plugin update webdecoy or update from the Plugins screen. We’ve also added a test that fails the build if this kind of load-order mistake comes back. Let me know if anything still looks off after updating.
