Hmm, just upgraded cider:

;; Connected to nREPL server - 
;; CIDER 0.16.0snapshot (package: 20171001.112), nREPL 0.2.12
;; Clojure 1.8.0, Java 1.8.0_144
;;     Docs: (doc function-name)
;;           (find-doc part-of-name)
;;   Source: (source function-name)
;;  Javadoc: (javadoc java-object-or-class)
;;     Exit: <C-c C-q>
;;  Results: Stored in vars *1, *2, *3, an exception in *e;
;; ======================================================================

and get the following when starting up my repl:

2017-10-01 19:51:42,055 [clojure-agent-send-off-pool-4] ERROR clojure.tools.nrepl.server - Unhandled REPL handler exception processing message {:op init-debugger, :print-level 10, :print-length 10, :session ff8d1f1f-6d17-4481-8df9-7977861ccf20, :id 6} 
clojure.lang.Compiler$CompilerException: java.lang.IllegalAccessError: with-safe-transport does not exist, compiling:(cider/nrepl/middleware/info.clj:1:1)
	at clojure.lang.Compiler.load(Compiler.java:7391)
	at clojure.lang.RT.loadResourceScript(RT.java:372)
	at clojure.lang.RT.loadResourceScript(RT.java:363)
	at clojure.lang.RT.load(RT.java:453)
	at clojure.lang.RT.load(RT.java:419)
	at clojure.core$load$fn__5677.invoke(core.clj:5893)
	at clojure.core$load.invokeStatic(core.clj:5892)
	at clojure.core$load.doInvoke(core.clj:5876)
	at clojure.lang.RestFn.invoke(RestFn.java:408)
	at clojure.core$load_one.invokeStatic(core.clj:5697)
	at clojure.core$load_one.invoke(core.clj:5692)
	at clojure.core$load_lib$fn__5626.invoke(core.clj:5737)
	at clojure.core$load_lib.invokeStatic(core.clj:5736)
	at clojure.core$load_lib.doInvoke(core.clj:5717)
	at clojure.lang.RestFn.applyTo(RestFn.java:142)
	at clojure.core$apply.invokeStatic(core.clj:648)
	at clojure.core$load_libs.invokeStatic(core.clj:5774)
	at clojure.core$load_libs.doInvoke(core.clj:5758)
	at clojure.lang.RestFn.applyTo(RestFn.java:137)
	at clojure.core$apply.invokeStatic(core.clj:648)
	at clojure.core$require.invokeStatic(core.clj:5796)
	at clojure.core$require.doInvoke(core.clj:5796)
	at clojure.lang.RestFn.invoke(RestFn.java:2088)
	at cider.nrepl.middleware.debug$eval7152$loading__5569__auto____7153.invoke(debug.clj:1)
	at cider.nrepl.middleware.debug$eval7152.invokeStatic(debug.clj:1)

Known issue?

I also notice errors after upgrading Cider.

ERROR clojure.tools.nrepl.server - Unhandled REPL handler exception processing message

That is when doing cider-connect to an existing nREPL session .

Version 20171001.112.

With cider 20170925.208 I saw other errors that I had never seen before.