diff --git a/backend/app/services/openclaw/gateway_compat.py b/backend/app/services/openclaw/gateway_compat.py
index ace829c4..3a1baf07 100644
--- a/backend/app/services/openclaw/gateway_compat.py
+++ b/backend/app/services/openclaw/gateway_compat.py
@@ -41,6 +41,16 @@ def _normalized_minimum_version() -> str:
 
 
 def _parse_version_parts(value: str) -> tuple[int, ...] | None:
+    """Parse version string into tuple of integers.
+
+    Supports various version formats including:
+    - Zero-padded: "2026.02.21-2" -> (2026, 2, 21)
+    - Non-zero-padded: "2026.2.21-2" -> (2026, 2, 21)
+    - With/without build suffix: "2026.2.9" or "2026.2.9-2"
+    - With/without 'v' prefix: "v2026.2.9" or "2026.2.9"
+
+    Build suffixes (e.g., "-2") are ignored during parsing.
+    """
     match = _VERSION_PATTERN.search(value.strip())
     if match is None:
         return None
@@ -138,7 +148,10 @@ def evaluate_gateway_version(
             current_version=None,
             message=(
                 "Unable to determine gateway version from runtime metadata. "
-                f"Minimum supported version is {min_version}."
+                "The gateway's config.schema, status, or health endpoints did not "
+                "return version information in any recognized format. "
+                f"Minimum supported version is {min_version}. "
+                "Please ensure your gateway is up to date and properly configured."
             ),
         )
 
diff --git a/backend/tests/test_gateway_version_compat.py b/backend/tests/test_gateway_version_compat.py
index 37f177cb..49fb266f 100644
--- a/backend/tests/test_gateway_version_compat.py
+++ b/backend/tests/test_gateway_version_compat.py
@@ -37,6 +37,73 @@ def test_evaluate_gateway_version_detects_old_runtime() -> None:
     assert "Minimum supported version is 2026.1.30" in (result.message or "")
 
 
+def test_parse_version_parts_handles_build_suffix() -> None:
+    """Test that version parsing works with build suffixes like -2."""
+    result = gateway_compat._parse_version_parts("2026.2.21-2")
+    assert result == (2026, 2, 21)
+
+
+def test_parse_version_parts_handles_zero_padded_month() -> None:
+    """Test that version parsing works with zero-padded months."""
+    result = gateway_compat._parse_version_parts("2026.02.21-2")
+    assert result == (2026, 2, 21)
+
+
+def test_parse_version_parts_handles_non_zero_padded_day() -> None:
+    """Test that version parsing works with non-zero-padded days."""
+    result = gateway_compat._parse_version_parts("2026.2.9")
+    assert result == (2026, 2, 9)
+
+
+def test_parse_version_parts_handles_zero_padded_day() -> None:
+    """Test that version parsing works with zero-padded days."""
+    result = gateway_compat._parse_version_parts("2026.02.09")
+    assert result == (2026, 2, 9)
+
+
+def test_evaluate_gateway_version_accepts_non_zero_padded_with_suffix() -> None:
+    """Test the exact scenario from the issue: non-zero-padded month with build suffix."""
+    result = gateway_compat.evaluate_gateway_version(
+        current_version="2026.2.21-2",
+        minimum_version="2026.02.9",
+    )
+
+    assert result.compatible is True
+    assert result.current_version == "2026.2.21-2"
+    assert result.minimum_version == "2026.02.9"
+
+
+def test_evaluate_gateway_version_accepts_zero_padded_with_suffix() -> None:
+    """Test that zero-padded version with suffix also works."""
+    result = gateway_compat.evaluate_gateway_version(
+        current_version="2026.02.21-2",
+        minimum_version="2026.02.9",
+    )
+
+    assert result.compatible is True
+    assert result.current_version == "2026.02.21-2"
+    assert result.minimum_version == "2026.02.9"
+
+
+def test_evaluate_gateway_version_compares_non_zero_padded_correctly() -> None:
+    """Test that non-zero-padded versions are compared correctly."""
+    # 2026.2.21 should be greater than 2026.2.9
+    result = gateway_compat.evaluate_gateway_version(
+        current_version="2026.2.21",
+        minimum_version="2026.2.9",
+    )
+
+    assert result.compatible is True
+
+    # 2026.2.5 should be less than 2026.2.9
+    result = gateway_compat.evaluate_gateway_version(
+        current_version="2026.2.5",
+        minimum_version="2026.2.9",
+    )
+
+    assert result.compatible is False
+
+
 @pytest.mark.asyncio
 async def test_check_gateway_runtime_compatibility_prefers_schema_version(
     monkeypatch: pytest.MonkeyPatch,