Salesforce Fact #976 | External service issue in apex
While referencing the external services in apex, we might encounter error like: Dependent class is invalid and needs recompilation: Class ExternalService.MyCallout : Unexpected token '2'. This is a known issue. The workaround is to replace '2XX' with '200' in the JSON of external service. Reference: https://help.salesforce.com/s/issue?id=a028c00000uW9g4