Premier Pro cc Timeline wont update on click

Please tell us your system specs: OS version, Premiere version, amount of RAM, Hardware specs including graphics card and your source properties and sequence settings.

does your system meet premiere requirements? 

https://helpx.adobe.com/premiere-pro/system-requirements.html

and by any chance are you working with screen recordings or video shot on a smart phone.  If so the problem may be sources with a variable frame rate which Premiere has problems with and it's nearly impossible to predict how the problems may manifest themselves.

use mediainfo to determine whether your source is variable or constant frame rate

https://mediaarea.net/en/MediaInfo/Download

if it's variable use handbrake to convert to constant frame rate

https://handbrake.fr
and here's a tutorial on how to use handbrake

https://www.youtube.com/watch?time_continue=34&v=xlvxgVREX-Y

Delete the Media Cache and Media Cache files:
https://community.adobe.com/t5/premiere-pro/faq-how-to-clear-your-media-cache-in-30-seconds-in-premiere-pro-2020/m-p/11017257/thread-id/260446?page=1

If that doesn't work,try resetting the preferences:
https://community.adobe.com/t5/premiere-pro/faq-how-to-reset-trash-preferences-in-premiere-pro/td-p/8236158?page=1

If that doesn't work, try resetting the Workspaces:
Reset a workspace
Reset the current workspace to return to its original, saved layout of panels.
1. Do one of the following:
• Click the Workspace menu icon and select Reset to Saved Layout.
• Choose Window > Workspace > Reset to Saved Layout.
from here:
https://helpx.adobe.com/premiere-pro/using/workspaces.html

If that doesn't work, try Preferences > Audio Hardware and set Input to None.

If that doesn’t work, try updating or rolling back your graphics driver directly from the video card manufacturer’s site. If NVIDIA, do a clean install of the latest Studio Driver (NOT the Game Driver).

If that doesn't work, try creating a new project and import the old one into it.

Also, please help us help you:
https://community.adobe.com/t5/premiere-pro/faq-what-information-should-i-provide-when-asking-a-question-on-this-forum/td-p/3929027?page=1