addition to server error tip

Author: j-atkins

docs/user-guide/tutorials/surf_research_cloud_setup.ipynb

@@ -26,7 +26,7 @@
     "Navigate to the [SURF Research Cloud Dashboard](https://portal.live.surfresearchcloud.nl/), and click \"access\" on the shared workspace.\n",
     "\n",
     "<div class=\"alert alert-block alert-success\"> \n",
-    "<b>**TIP**:</b> You may sometimes hit a server error when accessing the workspace. If this happens, keep on trying (refresh), as the server spin-up can be a bit overloaded at times, but should get through eventually. Unfortunately this is out of our control.\n",
+    "<b>**TIP**:</b> You may sometimes hit a server error when accessing the workspace. If this happens, keep on trying (refresh), as the server spin-up can be a bit overloaded at times, but should get through eventually. Unfortunately this is out of our control. Clearing your browser cache and cookies, and/or trying via an incognito/private window may also help.\n",
     "</div>\n",
     "\n",
     "## 3. Jupyter workspace layout and additional config\n",