Always connect to a server via LegacyGrpc when on macOS (#1275)

* Force LegacyGrpc connection when on macOS and connecting to a server

* Force LegacyGrpc connection when on macOS and using start_local_server

src/ansys/dpf/core/server.py

@@ -7,6 +7,7 @@
 import socket
 import weakref
 import copy
+import platform
 import inspect
 import warnings
 import traceback
@@ -225,6 +226,9 @@ def start_local_server(
     timed_out = False
     for _ in range(n_attempts):
         try:
+            # Force LegacyGrpc when on macOS
+            if platform.system() == "Darwin":
+                config = dpf.core.AvailableServerConfigs.LegacyGrpcServer
             server_type = ServerFactory.get_server_type_from_config(
                 config, ansys_path, docker_config
             )
@@ -309,7 +313,7 @@ def connect_to_server(
         The default is ``10``. Once the specified number of seconds
         passes, the connection fails.
     config: ServerConfig, optional
-        Manages the type of server connection to use.
+        Manages the type of server connection to use. Forced to LegacyGrpc on macOS.
     context: ServerContext, optional
         Defines the settings that will be used to load DPF's plugins.
         A DPF xml file can be used to list the plugins and set up variables. Default is
@@ -355,6 +359,10 @@ def connect():
         dpf.core._server_instances.append(weakref.ref(server))
         return server
 
+    # Enforce LegacyGrpc when on macOS
+    if platform.system() == 'Darwin':
+        config = dpf.core.AvailableServerConfigs.LegacyGrpcServer
+
     server_type = ServerFactory.get_remote_server_type_from_config(config)
     try:
         return connect()