when i open a state of florida highway safety and motor vehicle form that i have used for years, i am now getting a message in a box on the screen ' cannot find or create font arialnarrow' why ?

A couple of possible reasons.

Do you download the form from their website each time you need to fill it out? If so, it could be that they stopped embedding the font information in the pdf when they used to do that. In this case, you would need to ask them if they can embed that information (which you should always do when using a non-standard font. That's one of the big reasons to use pdf files.

Are you filing out the same form on a different computer? Again, non-embedded fonts could be the issue and you don't have that exact font on your new system. Same fix as above

If you filled out the exact same form that you downloaded and filled previously, it could be that you used to have that font and now for some reason you don't or your Reader isn't recognizing it any more. Also, could have been some change to the file (opened in a third party pdf viewer and saved...etc). Try re-downloading the file from where you originally got it. If that doesn't work, see one of the fixes above.