diff --git a/cloudinary_cli/cli_group.py b/cloudinary_cli/cli_group.py
index 210d0ac..9cd4147 100644
--- a/cloudinary_cli/cli_group.py
+++ b/cloudinary_cli/cli_group.py
@@ -14,7 +14,7 @@
 CONTEXT_SETTINGS = dict(max_content_width=shutil.get_terminal_size()[0], terminal_width=shutil.get_terminal_size()[0])
 
 
-@click.group(context_settings=CONTEXT_SETTINGS)
+@click.group(context_settings=CONTEXT_SETTINGS, invoke_without_command=True)
 @click.help_option()
 @click.version_option(cli_version, prog_name="Cloudinary CLI",
                       message=f"%(prog)s, version %(version)s\n"
@@ -24,10 +24,11 @@
               help="""Tell the CLI which account to run the command on by specifying an account environment variable."""
               )
 @click.option("-C", "--config_saved",
-              help="""Tell the CLI which account to run the command on by specifying a saved configuration - see 
+              help="""Tell the CLI which account to run the command on by specifying a saved configuration - see
               `config` command.""")
 @click_log.simple_verbosity_option(logger)
-def cli(config, config_saved):
+@click.pass_context
+def cli(ctx, config, config_saved):
     if config:
         refresh_cloudinary_config(config)
     elif config_saved:
@@ -40,4 +41,9 @@ def cli(config, config_saved):
     if not is_valid_cloudinary_config():
         logger.warning("No Cloudinary configuration found.")
 
+    # If no subcommand was invoked, show help and exit with code 0
+    if ctx.invoked_subcommand is None:
+        click.echo(ctx.get_help())
+        ctx.exit(0)
+
     return True
diff --git a/cloudinary_cli/core/__init__.py b/cloudinary_cli/core/__init__.py
index 5df20ac..7646e1c 100644
--- a/cloudinary_cli/core/__init__.py
+++ b/cloudinary_cli/core/__init__.py
@@ -8,7 +8,7 @@
 from cloudinary_cli.core.utils import url, utils
 from cloudinary_cli.core.overrides import resolve_command
 
-setattr(click.MultiCommand, "resolve_command", resolve_command)
+setattr(click.Group, "resolve_command", resolve_command)
 
 commands = [
     config,
diff --git a/cloudinary_cli/core/overrides.py b/cloudinary_cli/core/overrides.py
index 650f9c5..8eda507 100644
--- a/cloudinary_cli/core/overrides.py
+++ b/cloudinary_cli/core/overrides.py
@@ -1,14 +1,19 @@
-from click.parser import split_opt
 from click.utils import make_str
 from cloudinary import api, uploader
 from cloudinary.uploader import upload as original_upload
 from cloudinary.utils import cloudinary_url as original_cloudinary_url
+from cloudinary_cli.utils.utils import split_opt
 
 
 # overrides click.MultiCommand.resolve_command
 def resolve_command(self, ctx, args):
     # Patch the `resolve_command` function to enable simple commands (eg. cld resource)
     # Only core commands from API and modules are registered (eg. cld admin)
+
+    # Handle empty args (when CLI is invoked with no arguments)
+    if not args:
+        return None, None, []
+
     cmd_name = make_str(args[0])
     original_cmd_name = cmd_name
 
diff --git a/cloudinary_cli/modules/sync.py b/cloudinary_cli/modules/sync.py
index d0acb65..8e82c82 100644
--- a/cloudinary_cli/modules/sync.py
+++ b/cloudinary_cli/modules/sync.py
@@ -300,7 +300,7 @@ def _normalize_remote_file_names(self, remote_files, local_files):
 
     def _local_candidates(self, candidate_path):
         filename, extension = path.splitext(candidate_path)
-        r = re.compile(f"({candidate_path}|{filename} \(\d+\){extension})")
+        r = re.compile(f"({candidate_path}|{filename} \\(\\d+\\){extension})")
         # sort local files by base name (without ext) for accurate results.
         return dict(sorted({f: self.local_files[f]["etag"] for f in filter(r.match, self.local_files.keys())}.items(),
                            key=lambda f: path.splitext(f[0])[0]))
diff --git a/cloudinary_cli/utils/utils.py b/cloudinary_cli/utils/utils.py
index 1e1ed3d..e0c69a4 100644
--- a/cloudinary_cli/utils/utils.py
+++ b/cloudinary_cli/utils/utils.py
@@ -379,3 +379,25 @@ def duplicate_values(items, value_key, key_of_interest=None):
         rev_multidict.setdefault(value[value_key], set()).add(value[key_of_interest] if key_of_interest is not None else key)
 
     return {key: values for key, values in rev_multidict.items() if len(values) > 1}
+
+
+def split_opt(opt):
+    """
+    Splits an option string into prefix and value parts.
+
+    This function replaces the deprecated click.parser.split_opt import.
+    Returns a tuple of (prefix, value) where prefix is the option prefix
+    (like '-' or '--') and value is the remaining part, or ('', opt)
+    if it doesn't look like an option.
+
+    :param opt: The option string to parse.
+    :type opt: str
+    :return: Tuple of (prefix, value)
+    :rtype: tuple
+    """
+    first = opt[:1]
+    if first.isalnum():
+        return '', opt
+    if opt[1:2] == first:
+        return opt[:2], opt[2:]
+    return first, opt[1:]