The most likely cause of the issue is A. The target system's API functionality has been deprecated. API deprecation is the process of gracefully discontinuing an API. The process starts by first informing the customers that the API is no longer actively supported even though it will be operational and suggesting them to migrate to an alternate or latest version of the API1. However, sometimes the API functionality may change or be removed without proper notice or documentation, which can break the existing applications that rely on the API. According to the web search results, API deprecation is a common challenge for configuration management tools. Therefore, if the target system's API functionality has been deprecated after the updates, the configuration management tool may no longer work as expected.