One common problem with using the OData REST API Patch in D365FO with X++ is the lack of support for complex data types, such as arrays or nested objects. When attempting to update a record with such complex data types using the Patch request, the API may not be able to properly serialize the data, resulting in errors or unexpected behavior. Another potential issue is the limited support for batch operations when using the Patch request. While the API does support batch requests, it may not be as efficient or flexible as other methods for updating multiple records at once. Additionally, handling error responses and debugging issues with the Patch request can be more challenging in X++ compared to other programming languages due to the limited tooling and error handling capabilities in D365FO. Overall, developers should carefully consider the limitations and potential challenges of using the OData REST API Patch in D365FO with X++ and explore alternative approaches or workarounds if necessary.

---