I suggest you to check if any key or button is stuck on Keyboard or mouse.
Meanwhile,you can provide us with your project to see if this is any generic issue with PC4.0
Close all the unnecessary tabs on which you are not working in PC4.0.
"Ln 1 Col 1 INS" blinking because the code is stuck at a certain line no. in certain opened file in a tab.
I resolved this issue by going to the PSoC exe file properties and setting the "Compatibility" to "Windows 8".