We are deploying our metadata through ANT migration tool.there are flows which are calling apex class and some flows are getting called from process builder.we have test class for apex class and flows as well. During validation test classes are getting failed with error 'CANNOT_EXECUTE_FLOW_TRIGGER'.
Note that all test classes are getting passed via 'Run All Tests' in Source Org. However during deployment validation exact same test classes are getting failed.
What is the root cause of thisissue?