Hi @clarkjohnathan999. Does the problem still occur after you put the Arduino IDE into portable mode? There are several different keywords.txt files and I'm not sure which one the IDE is complaining about. Running the IDE in portable mode reduces the number of potential keywords.txt files that need to be loaded. So the information about whether or not it occurs will narrow down the source of the problem.
The first thing you will need to do is, if you don't have one already, make a non-Windows Store installation of the Arduino IDE. Due to the additional security restrictions Windows puts on apps, it's not possible to put the Windows Store version in portable mode. You can use the version you get from the "Windows ZIP file" download link on the Software page if you don't want to mess with your existing IDE installation.
In order to put the Arduino IDE in portable mode, just open the Arduino IDE installation folder in Windows Explorer and create a new folder there named portable.
Once that is done, try starting the modified installation of the Arduino IDE and then tell us whether the error still occurs.