Background Jobs and The resource you are looking for is not available

I keep on getting a pop up message of “The resource you are looking for is not available” when viewing or creating a new transaction on all of my doctypes. Can you help me to figure out what is the cause of it.

Also, upon checking the background jobs are too many now when I started receiving the pop up message “The resource you are looking for is not available”.

This always pop up to all doctype after we upgrade the version of the ERPNEXT.

Installed Apps

ERPNext: v12.5.2 (version-12)
Frappe Framework: v12.3.0 (version-12)

How can the pop up message be removed?