Not sure if you have viewed these forum topics, created by others who had problems when running FMPA14.
Also not, sure what you mean by 'first window' ... are you referring to the Launch Centre?
Here's a potential solution if so:
Apologies if you have already seen this.
By first window, I did mean the first window to open in a solution. However I tried restoring the standard fonts in the font book and it seems to have resolved the issue.