I tried to update Panel version used in my app from 0.11.3 to 0.12.1 on my deployment server. However, when I run it, nothing was shown. I checked the google chrome console and found the error below.
In my deployment server, I am using docker and bind the panel port number to the accessed port number.
I thought that this problem comes from my Python environments or the code. However, I could not reproduced the error when I rebuild the Docker images and using another port number. My code also work on the development server.
I solved this problem by removing the cache and cookies of my browser (Google Chrome). After I cleaned it, the error is gone and it work as expected.
I am writing it, so if someone has the same problem, they can find the solution.
Would you mind also filing a bug report @Arifin . Every bode experiences this problem when ever Panel/ Bokeh is upgraded and there is some important change.
Current Solution: Hard Refresh Browser
Future Solution: Panel just handles this.