In Version 19, we increased the limit of user-defined fields in each file to 450. This number is in addition to any protected fields in the file. In Version 18 and prior, you were limited to 435 fields total in each file, which included both user-defined and protected fields.
If you want to see how many user-defined fields you currently have in any given file, you can run the File Definition Report (Reports | File Definition Report). The following fields on this report may be of particular interest:
For more information on the File Definition Report, including fields not listed here, refer to the PracticeMaster Report Pack.