diff --git a/confluent_server/aiohmi/ipmi/oem/lenovo/config.py b/confluent_server/aiohmi/ipmi/oem/lenovo/config.py
index 7ae16c66..35e72d3b 100644
--- a/confluent_server/aiohmi/ipmi/oem/lenovo/config.py
+++ b/confluent_server/aiohmi/ipmi/oem/lenovo/config.py
@@ -147,8 +147,12 @@ def _eval_conditional(expression, cfg, setting):
 class LenovoFirmwareConfig(object):
     def __init__(self, xc, useipmi=True):
         if not etree:
-            raise Exception("python-lxml and python-eficompressor required "
-                            "for this function")
+            # Not a bare Exception. Confluent has no handler for one, so a
+            # missing optional dependency showed as "Unexpected Error" and hid
+            # the message below, which already names what to install.
+            raise pygexc.UnsupportedFunctionality(
+                "python-lxml and python-eficompressor required "
+                "for this function")
         if useipmi:
             self.connection = xc.ipmicmd
         else:
diff --git a/confluent_server/aiohmi/redfish/oem/generic.py b/confluent_server/aiohmi/redfish/oem/generic.py
index b44bc253..ba739fb4 100644
--- a/confluent_server/aiohmi/redfish/oem/generic.py
+++ b/confluent_server/aiohmi/redfish/oem/generic.py
@@ -1794,7 +1794,14 @@ class OEMHandler(object):
                 errmsg = ','.join(errmsg)
                 raise exc.RedfishError(errmsg)
             except (ValueError, KeyError):
-                raise exc.PyghmiException(str(url) + ":" + res[0])
+                # Reached by an html 404 page, or anything else that is not
+                # the JSON error document. res[0] is bytes there, so building
+                # the message crashed and the caller saw that TypeError
+                # instead of the status and the body.
+                body = res[0]
+                if isinstance(body, bytes):
+                    body = body.decode('utf-8', errors='replace')
+                raise exc.PyghmiException('{0}:{1}'.format(url, body))
         if payload is None and method is None:
             self._urlcache[url] = {
                 'contents': res[0],