Undefined Symbols error

Default install with cocoapods, xcode 9.2. Can’t get past this error. Any clues would be appreciated.

Undefined symbols for architecture arm64:
OBJC_CLASS_ESTRequestGetBeaconsDetails", referenced from: objc-class-ref in EstimoteUnity.o "_OBJC_CLASS__ESTConfig”, referenced from:
objc-class-ref in EstimoteUnity.o
OBJC_CLASS$_ESTBeaconManager”, referenced from:
objc-class-ref in EstimoteUnity.o
ld: symbol(s) not found for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

I think this is what usually happens when you forget to open .xcworkspace (white icon) instead of .xcodeproj (blue icon) after installing Pods in your project.