Add possible error in start up script

Signed-off-by: Tyler Gu <jiaweig3@illinois.edu>

README.md

@@ -47,13 +47,27 @@ and keep hitting `next` to create the experiment.
 You should see that CloudLab starts to provision the machine and our profile will run a StartUp
   script to set the environment up.
 
-The start up would take around 10 minutes.
-Please patiently wait for both the `Status` and `Startup` become `Ready`.
+The start up would take around 20 minutes.
+Please patiently wait for the `Status` to become `Ready` and `Startup` become `Finished`.
 After that, Acto is installed at the `workdir/acto` directory under your `$HOME` directory.
 
 Access the machine using `ssh` or through the `shell` provided by the CloudLab Web UI.
 Please proceed to the [Kick-the-tire Instructions](#3-kick-the-tire-instructions-10-minutes) to validate.
 
+### Seeting the `Startup` status become `exit(2)`?
+<details><summary>Click to show details</summary>
+
+There are sometimes transient network issues, which cause the `pip` step in the startup script not able to connect to the server.
+To fix the problem, either recreate the experiment using the profile, or ssh into the machine and run the following commands:
+```sh
+sudo su - geniuser
+bash /local/repository/scripts/cloudlab_startup_run_by_geniuser.sh
+exit
+```
+
+</details>
+
+
 ### Seeing error message from CloudLab `No available physical nodes of type c6420 found (1 requested)`?
 <details><summary>Click to show details</summary>