diff --git a/server/secops-soar/README.md b/server/secops-soar/README.md
index 97e52fb5..96c2f7b6 100644
--- a/server/secops-soar/README.md
+++ b/server/secops-soar/README.md
@@ -119,6 +119,22 @@ $Env:SOAR_APP_KEY = "your-soar-app-key"
 $Env:SOAR_INTEGRATIONS = "ServiceNow,CSV,Siemplify"
 ```
 
+## Troubleshooting
+
+If the server shuts down at startup with an error like `Failed to fetch valid
+scopes from SOAR due to an SSL certificate verification error`, this is a
+local CA certificate problem, not incorrect `SOAR_URL`/`SOAR_APP_KEY` values.
+Install the certifi CA bundle:
+
+- **macOS:** run `Install Certificates.command` from your Python install,
+  e.g. `/Applications/Python\ 3.12/Install\ Certificates.command` (match the
+  Python minor version you're running).
+- **Linux/Windows:** point `SSL_CERT_FILE` at the certifi bundle, e.g.
+  `export SSL_CERT_FILE=$(python -m certifi)` (or the PowerShell equivalent
+  `$Env:SSL_CERT_FILE = (python -m certifi)`).
+
+See `docs/usage_guide.md` for further details.
+
 ## Requirements
 
 -   Python 3.11+
diff --git a/server/secops-soar/secops_soar_mcp/bindings.py b/server/secops-soar/secops_soar_mcp/bindings.py
index 077aafda..2e99db81 100644
--- a/server/secops-soar/secops_soar_mcp/bindings.py
+++ b/server/secops-soar/secops_soar_mcp/bindings.py
@@ -14,7 +14,9 @@
 """Bindings for the SOAR client."""
 
 import os
+import ssl
 
+import aiohttp
 import dotenv
 from logger_utils import get_logger
 from secops_soar_mcp.http_client import HttpClient
@@ -28,9 +30,23 @@
 http_client: HttpClient = None
 valid_scopes = set()
 
+_CERTIFICATE_ERROR_MESSAGE = (
+    "Failed to fetch valid scopes from SOAR due to an SSL certificate "
+    "verification error. This is usually a local CA certificate "
+    "configuration issue, not incorrect SOAR credentials. Install the "
+    "certifi CA bundle, e.g. run Python's `Install Certificates.command` "
+    "(macOS) or point SSL_CERT_FILE at the output of `python -m certifi`. "
+    "See the 'Troubleshooting' section in README.md or setup notes in "
+    "docs/usage_guide.md for setup steps. "
+    "Shutting down..."
+)
+
 
 async def _get_valid_scopes():
-    valid_scopes_list = await http_client.get(consts.Endpoints.GET_SCOPES)
+    try:
+        valid_scopes_list = await http_client.get(consts.Endpoints.GET_SCOPES)
+    except (ssl.SSLError, aiohttp.ClientSSLError) as e:
+        raise RuntimeError(_CERTIFICATE_ERROR_MESSAGE) from e
     if valid_scopes_list is None:
         raise RuntimeError(
             "Failed to fetch valid scopes from SOAR, please make sure you have configured the right SOAR credentials. Shutting down..."
diff --git a/server/secops-soar/secops_soar_mcp/http_client.py b/server/secops-soar/secops_soar_mcp/http_client.py
index 04afc16d..13aa5ed1 100644
--- a/server/secops-soar/secops_soar_mcp/http_client.py
+++ b/server/secops-soar/secops_soar_mcp/http_client.py
@@ -14,6 +14,7 @@
 """HTTP client for making requests to the SecOps SOAR API."""
 
 import json
+import ssl
 from typing import Any, Dict
 
 import aiohttp
@@ -64,6 +65,10 @@ async def get(
                 return await response.json()
         except aiohttp.ClientResponseError as e:
             logger.debug("HTTP error occurred: %s", e)
+        except (ssl.SSLError, aiohttp.ClientSSLError):
+            # Don't mask certificate configuration problems as a plain
+            # "no data" result; callers need to see and report on these.
+            raise
         except Exception as e:
             logger.debug("An error occurred: %s", e)
         return None
@@ -95,6 +100,10 @@ async def post(
                 return json.loads(decoded_data)
         except aiohttp.ClientResponseError as e:
             logger.debug("HTTP error occurred: %s", e)
+        except (ssl.SSLError, aiohttp.ClientSSLError):
+            # Don't mask certificate configuration problems as a plain
+            # "no data" result; callers need to see and report on these.
+            raise
         except Exception as e:
             logger.debug("An error occurred: %s", e)
         return None
@@ -124,6 +133,10 @@ async def patch(
                 return await response.json()
         except aiohttp.ClientResponseError as e:
             logger.debug("HTTP error occurred: %s", e)
+        except (ssl.SSLError, aiohttp.ClientSSLError):
+            # Don't mask certificate configuration problems as a plain
+            # "no data" result; callers need to see and report on these.
+            raise
         except Exception as e:
             logger.debug("An error occurred: %s", e)
         return None
diff --git a/server/secops-soar/tests/unit/__init__.py b/server/secops-soar/tests/unit/__init__.py
new file mode 100644
index 00000000..e69de29b
diff --git a/server/secops-soar/tests/unit/conftest.py b/server/secops-soar/tests/unit/conftest.py
new file mode 100644
index 00000000..efa02d43
--- /dev/null
+++ b/server/secops-soar/tests/unit/conftest.py
@@ -0,0 +1,23 @@
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import pytest_asyncio
+
+
+@pytest_asyncio.fixture(loop_scope="session", autouse=True)
+async def setup_bindings():
+    """Overrides tests/conftest.py's fixture: these unit tests mock
+    bindings/http_client directly and must not require real SOAR
+    credentials or network access."""
+    yield
diff --git a/server/secops-soar/tests/unit/test_certificate_error_handling.py b/server/secops-soar/tests/unit/test_certificate_error_handling.py
new file mode 100644
index 00000000..98549f15
--- /dev/null
+++ b/server/secops-soar/tests/unit/test_certificate_error_handling.py
@@ -0,0 +1,105 @@
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Tests that certificate errors get a helpful message instead of the
+generic "wrong SOAR credentials" one, and that HttpClient doesn't swallow
+SSL errors as a plain None result (see issue #191)."""
+
+import ssl
+from unittest import mock
+
+import aiohttp
+import pytest
+
+from secops_soar_mcp import bindings
+from secops_soar_mcp.http_client import HttpClient
+
+
+class _RaisingSession:
+    """Minimal aiohttp session stand-in whose .get() raises."""
+
+    def __init__(self, exc: Exception):
+        self._exc = exc
+
+    def get(self, *args, **kwargs):
+        raise self._exc
+
+    async def close(self):
+        pass
+
+
+@pytest.mark.asyncio
+async def test_http_client_get_reraises_ssl_error():
+    client = HttpClient("https://example.com", "app-key")
+    client._session = _RaisingSession(ssl.SSLCertVerificationError("bad cert"))
+
+    with pytest.raises(ssl.SSLError):
+        await client.get("/some/endpoint")
+
+
+@pytest.mark.asyncio
+async def test_http_client_get_swallows_generic_connection_error():
+    client = HttpClient("https://example.com", "app-key")
+    client._session = _RaisingSession(aiohttp.ClientConnectionError("refused"))
+
+    assert await client.get("/some/endpoint") is None
+
+
+@pytest.mark.asyncio
+async def test_get_valid_scopes_reports_certificate_issue_not_credentials():
+    with (
+        mock.patch.object(
+            bindings,
+            "http_client",
+            new=mock.AsyncMock(get=mock.AsyncMock(side_effect=ssl.SSLCertVerificationError())),
+        ),
+        pytest.raises(RuntimeError) as exc_info,
+    ):
+        await bindings._get_valid_scopes()
+
+    message = str(exc_info.value)
+    assert "certifi" in message.lower()
+    assert "certificate" in message.lower()
+    assert "not" in message.lower() and "credentials" in message.lower()
+
+
+@pytest.mark.asyncio
+async def test_get_valid_scopes_still_blames_credentials_when_no_data():
+    with (
+        mock.patch.object(
+            bindings,
+            "http_client",
+            new=mock.AsyncMock(get=mock.AsyncMock(return_value=None)),
+        ),
+        pytest.raises(RuntimeError) as exc_info,
+    ):
+        await bindings._get_valid_scopes()
+
+    assert "credentials" in str(exc_info.value).lower()
+
+
+@pytest.mark.asyncio
+async def test_get_valid_scopes_reports_certificate_issue_on_client_ssl_error():
+    conn_key = aiohttp.client_reqrep.ConnectionKey("example.com", 443, True, True, None, None, None)
+    client_ssl_err = aiohttp.ClientSSLError(conn_key, OSError("handshake failed"))
+    with (
+        mock.patch.object(
+            bindings,
+            "http_client",
+            new=mock.AsyncMock(get=mock.AsyncMock(side_effect=client_ssl_err)),
+        ),
+        pytest.raises(RuntimeError) as exc_info,
+    ):
+        await bindings._get_valid_scopes()
+    assert "certificate" in str(exc_info.value).lower()