--- a/util/startup.lua	Fri Aug 28 12:51:40 2020 +0100
+++ b/util/startup.lua	Fri Aug 28 12:54:31 2020 +0100
@@ -547,7 +547,7 @@
 end
 
 function startup.init_errors()
-	require "util.error".configure(config.get("*", "error_library"));
+	require "util.error".configure(config.get("*", "error_library") or {});
 end
 
 function startup.make_host(hostname)