Hi,
System is correct. You should create Project Definition 00-ADVG-350. Your PRJ ID in Coding mask is 00 and is it should be as it is at time of Project creation. 00 PRJID in Coding mask does not means you can use any number (like 14, you used).
Create Project definition 00-ADVG-350 and system will allow you to create
Also if you want to create only 14-ADVG-350, you should create a new mask as:
14-XXXX-XXX-XXXX
Regards
Shishir