Is It Common That a Second Crown Be Made Because the First One Did Not Fit Correctly?

I would no say it a common thing, however it certainly does happen. Remember the crown was made to fit EXACTLY from the time of impressions. Distortions and other factors can cause the fabrication to be slightly off.

There are numerous reasons why a crown may not fit and EVERY DENTIST who ever practiced dentistry has had crowns come back from the lab that didn't fit perfectly.  The good news is that your dentist recognized that and is taking the effort to correct the problem.  Shows your dentist has your best interest in mind and is a man of ethics and principle!  You would not believe how many dentists cement in crowns that do not fit properly, and then are later discovered and then have to be redone from start.  Thank your dentist for his high standards and accept the fact that things like this are not uncommon in dentistry and he is doing the best/right thing for you.

If the preparation of the site is correct,the impression material optimate,and lab well done,crowns fit properly,commonly,

Remember crowns are custom made,milimetrically they need to fit.