Validation failed for userAgent (php library)

*I'm trying to get the Adwords sandbox api to work, and this is the error message I keep getting:* An error has occurred: Validation failed for [userAgent] with value []: The prop erty userAgent is required and cannot be NULL, the empty string, or the default [] *Here is the configuration sett

Validation failed for userAgent (php)

*I'm trying to get the Adwords sandbox api to work, and this is the error message I keep getting:* An error has occurred: Validation failed for [userAgent] with value []: The prop erty userAgent is required and cannot be NULL, the empty string, or the default [] *Here is the configuration sett