HELP! Keep getting LiquidCrystal .h no such file

I have already installed a code using this directory, now, I have a new code which was supposed to fix a decimal place and all of the versions will not run because of the above message. Already reinstalled the IDE.

Are you using the Arduino Web Editor?

Sounds as if you are using one of the older LiquidCrystal libraries.

Is this for a 1602 or 2004 or similar display?

Install the HD44780 library using the Library Manager and work through the examples for that library. It is much "smarter" than the older libraries and should pretty much sort everything out for you.