Print the error as an error log and raise the same exception we got

synapse/handlers/acme.py

@@ -22,10 +22,17 @@ from twisted.web import server, static
 from twisted.web.resource import Resource
 
 from synapse.app import check_bind_error
-from synapse.config import ConfigError
 
 logger = logging.getLogger(__name__)
 
+ACME_REGISTER_FAIL_ERROR = """
+Failed to register with the ACME provider. This is likely happening because the install
+is new, and ACME v1 has been deprecated by Let's Encrypt and is disabled for installs set
+up after November 2019.
+At the moment, Synapse doesn't support ACME v2. For more info and alternative solution,
+check out https://github.com/matrix-org/synapse/blob/master/docs/ACME.md#deprecation-of-acme-v1
+------------------------------------------------------"""
+
 
 class AcmeHandler(object):
     def __init__(self, hs):
@@ -76,14 +83,8 @@ class AcmeHandler(object):
         try:
             yield self._issuer._ensure_registered()
         except Exception:
-            raise ConfigError(
-                "Failed to register with the ACME provider. This is likely happening"
-                " because the install is new, and ACME v1 has been deprecated by Let's"
-                " Encrypt and is disabled for installs set up after November 2019. At the"
-                " moment, Synapse doesn't support ACME v2. For more info and alternative"
-                " solution, check out https://github.com/matrix-org/synapse/blob/master"
-                "/docs/ACME.md#deprecation-of-acme-v1"
-            )
+            logger.error(ACME_REGISTER_FAIL_ERROR)
+            raise
 
     @defer.inlineCallbacks
     def provision_certificate(self):