diff --git a/common/uxbox/common/spec.cljc b/common/uxbox/common/spec.cljc
index 187adcb37..920f8f1b8 100644
--- a/common/uxbox/common/spec.cljc
+++ b/common/uxbox/common/spec.cljc
@@ -9,7 +9,6 @@
   (:refer-clojure :exclude [assert])
   #?(:cljs (:require-macros [uxbox.common.spec :refer [assert]]))
   (:require
-   #?(:clj [datoteka.core :as fs])
    #?(:clj [clojure.spec.alpha :as s]
       :cljs [cljs.spec.alpha :as s])
    [expound.alpha :as expound]
@@ -85,15 +84,6 @@
     v
     ::s/invalid))
 
-#?(:clj
-   (defn path-conformer
-     [v]
-     (cond
-       (string? v) (fs/path v)
-       (fs/path? v) v
-       :else ::s/invalid)))
-
-
 ;; --- Default Specs
 
 (s/def ::inst inst?)
@@ -107,7 +97,6 @@
 (s/def ::not-empty-string (s/and string? #(not (str/empty? %))))
 (s/def ::url string?)
 (s/def ::fn fn?)
-#?(:clj (s/def ::path (s/conformer path-conformer str)))
 
 ;; --- Macros
 
diff --git a/common/uxbox/common/uuid_impl.js b/common/uxbox/common/uuid_impl.js
index 677a698a0..88c1db3dd 100644
--- a/common/uxbox/common/uuid_impl.js
+++ b/common/uxbox/common/uuid_impl.js
@@ -20,8 +20,13 @@ function fill(buf) {
   return buf;
 };
 
+// NOTE: NodeJS compatibility
+if (typeof require === "function") {
+  global.crypto = require("crypto");
+}
+
 if (global.crypto === undefined) {
-  console.warn("No high quality RNG available, switching back to Math.random.", platform);
+  console.warn("No high quality RNG available, switching back to Math.random.");
 
   fill = function(buf) {
     for (let i = 0, r; i < buf.length; i++) {
diff --git a/exporter/shadow-cljs.edn b/exporter/shadow-cljs.edn
index 3fd9962bc..c5d4f9c60 100644
--- a/exporter/shadow-cljs.edn
+++ b/exporter/shadow-cljs.edn
@@ -1,9 +1,12 @@
 {:dependencies
  [[funcool/promesa "5.1.0"]
+  [danlentz/clj-uuid "0.1.9"]
   [funcool/cuerdas "2020.03.26-3"]
   [lambdaisland/glogi "1.0.63"]
-  [metosin/reitit-core "0.5.2"]]
- :source-paths ["src"]
+  [metosin/reitit-core "0.5.2"]
+  [com.cognitect/transit-cljs "0.8.264"]]
+
+ :source-paths ["src" "../common"]
  :nrepl {:port 3497}
 
  :builds
diff --git a/exporter/src/app/http.cljs b/exporter/src/app/http.cljs
index fef416e13..ee6273342 100644
--- a/exporter/src/app/http.cljs
+++ b/exporter/src/app/http.cljs
@@ -4,7 +4,9 @@
    [lambdaisland.glogi :as log]
    [app.browser :as bwr]
    [app.http.screenshot :refer [bitmap-handler]]
+   [app.util.transit :as t]
    [reitit.core :as r]
+   [cuerdas.core :as str]
    ["koa" :as koa]
    ["http" :as http])
   (:import
@@ -29,6 +31,31 @@
                :params params
                :query-params qparams)))))
 
+(defn- handle-error
+  [error request]
+  (let [{:keys [type message code] :as data} (ex-data error)]
+    (cond
+      (= :validation type)
+      (let [header (get-in request [:headers "accept"])]
+        (if (and (str/starts-with? header "text/html")
+                 (= :spec-validation (:code data)))
+          {:status 400
+           :headers {"content-type" "text/html"}
+           :body (str "<pre style='font-size:16px'>" (:explain data) "</pre>\n")}
+          {:status 400
+           :headers {"x-metadata" (t/encode data)}
+           :body ""}))
+
+      :else
+      (do
+        (log/error :msg "Unexpected error"
+                   :error error)
+        {:status 500
+         :headers {"x-metadata" (t/encode {:type :unexpected
+                                           :message (ex-message error)})}
+         :body ""}))))
+
+
 (defn- handle-response
   [ctx {:keys [body headers status] :or {headers {} status 200}}]
   (run! (fn [[k v]] (.set ^js ctx k v)) headers)
@@ -36,15 +63,30 @@
   (set! (.-status ^js ctx) status)
   nil)
 
+(defn- parse-headers
+  [ctx]
+  (let [orig (unchecked-get ctx "headers")]
+    (persistent!
+     (reduce #(assoc! %1 %2 (unchecked-get orig %2))
+             (transient {})
+             (js/Object.keys orig)))))
+
 (defn- wrap-handler
   [f extra]
   (fn [ctx]
     (let [cookies (unchecked-get ctx "cookies")
-          request (assoc extra :ctx ctx :cookies cookies)]
+          headers (parse-headers ctx)
+          request (assoc extra
+                         :ctx ctx
+                         :headers headers
+                         :cookies cookies)]
       (-> (p/do! (f request))
-          (p/then (fn [rsp]
-                    (when (map? rsp)
-                      (handle-response ctx rsp))))))))
+          (p/then  (fn [rsp]
+                     (when (map? rsp)
+                       (handle-response ctx rsp))))
+          (p/catch (fn [err]
+                     (->> (handle-error err request)
+                          (handle-response ctx))))))))
 
 (def routes
   [["/export"
diff --git a/exporter/src/app/http/screenshot.cljs b/exporter/src/app/http/screenshot.cljs
index efd94b5ec..d8582f3ed 100644
--- a/exporter/src/app/http/screenshot.cljs
+++ b/exporter/src/app/http/screenshot.cljs
@@ -2,7 +2,10 @@
   (:require
    [app.browser :as bwr]
    [app.config :as cfg]
-   [promesa.core :as p]))
+   [cljs.spec.alpha :as s]
+   [promesa.core :as p]
+   [uxbox.common.exceptions :as exc :include-macros true]
+   [uxbox.common.spec :as us]))
 
 (defn- load-and-screenshot
   [page url cookie]
@@ -27,13 +30,17 @@
               (load-and-screenshot page url cookie)))]
     (bwr/exec! browser on-browser)))
 
+(s/def ::page-id ::us/uuid)
+(s/def ::object-id ::us/uuid)
+(s/def ::bitmap-handler-params
+  (s/keys :req-un [::page-id ::object-id]))
+
 (defn bitmap-handler
   [{:keys [params browser cookies] :as request}]
-  (let [page-id   (get-in params [:query :page-id])
-        object-id (get-in params [:query :object-id])
-        token     (.get ^js cookies "auth-token")]
-    (-> (take-screenshot browser {:page-id page-id
-                                  :object-id object-id
+  (let [params (us/conform ::bitmap-handler-params (:query params))
+        token  (.get ^js cookies "auth-token")]
+    (-> (take-screenshot browser {:page-id (:page-id params)
+                                  :object-id (:object-id params)
                                   :token token})
         (p/then (fn [result]
                   {:status 200
diff --git a/exporter/src/app/util/transit.cljs b/exporter/src/app/util/transit.cljs
new file mode 100644
index 000000000..1f3bfd9b8
--- /dev/null
+++ b/exporter/src/app/util/transit.cljs
@@ -0,0 +1,32 @@
+;; This Source Code Form is subject to the terms of the Mozilla Public
+;; License, v. 2.0. If a copy of the MPL was not distributed with this
+;; file, You can obtain one at http://mozilla.org/MPL/2.0/.
+;;
+;; This Source Code Form is "Incompatible With Secondary Licenses", as
+;; defined by the Mozilla Public License, v. 2.0.
+;;
+;; Copyright (c) 2020 UXBOX Labs SL
+
+(ns app.util.transit
+  (:require
+   [cognitect.transit :as t]))
+
+;; --- Transit Handlers
+
+(def ^:private +read-handlers+
+  {"u" uuid})
+
+(def ^:private +write-handlers+
+  {})
+
+;; --- Public Api
+
+(defn decode
+  [data]
+  (let [r (t/reader :json {:handlers +read-handlers+})]
+    (t/read r data)))
+
+(defn encode
+  [data]
+  (let [w (t/writer :json {:handlers +write-handlers+})]
+    (t/write w data)))
diff --git a/frontend/src/uxbox/main/ui/workspace/sidebar/options.cljs b/frontend/src/uxbox/main/ui/workspace/sidebar/options.cljs
index afd564787..b4a1b086b 100644
--- a/frontend/src/uxbox/main/ui/workspace/sidebar/options.cljs
+++ b/frontend/src/uxbox/main/ui/workspace/sidebar/options.cljs
@@ -14,6 +14,7 @@
    [cuerdas.core :as str]
    [rumext.alpha :as mf]
    [uxbox.common.spec :as us]
+   [uxbox.main.data.messages :as dm]
    [uxbox.main.data.workspace :as udw]
    [uxbox.main.refs :as refs]
    [uxbox.main.store :as st]
@@ -67,8 +68,10 @@
                    (swap! loading? not)
                    (->> (request-screenshot (:id page) (:id shape))
                         (rx/subs
-                         (fn [{:keys [status body]}]
-                           (trigger-download (:name shape) body))
+                         (fn [{:keys [status body] :as response}]
+                           (if (= status 200)
+                             (trigger-download (:name shape) body)
+                             (st/emit! (dm/error (tr "errors.unexpected-error")))))
                          (constantly nil)
                          (fn []
                            (swap! loading? not)))))]