AI extent reaches 2GB and returns error 4524

Database crashes with 6081 and 3779 errors on a variable AI extent
Database start fails with error 4524 returned on variable ai extent
Trying to start database returns 4524
Trying to disable after-imaging returns 4524

Variable ai extent has reached 2GB in size

Method 1: Enable Large Files

If an Enterprise Database License is in use and the FileSystem support largefiles, enable the largefiles feature (available since Progress 9.1D) on the database then restart it.  Refer to Article

• Extent exceeds 2 GB file size limit - Enable large file support   

Method 2: Empty or Add more AI Extents

If the variable AI Extent is within 32-bytes of 2GB Stat, a few notes need to be written in the current AI extent when it is switched:

1. Ensure that all FULL extents have been emptied with  RFUTIL -C aimage empty
2. Add more AI Extents with PROSTRCT add

Unless the variable extent that has reached the 2GB limit is the last extent in the sequence, after emptying and or adding AI files, they will need to be re-ordered.  Refer to Article

•  How to reorder ai extents after adding new ai extents to the database   

Method 3: Fix the AI extents then Re-enable After-Imaging

1. Backup all database files with OS utilties.
2. Copy any of the other empty or smaller ai extent to replace the ai extent reported in the 4524 message.
3. Fix the inconsistencies in the file structure with "prostrct unlock <dbname>"
4. Disable AI: "rfutil <dbname> -C aimage end"
5. Remove all AI extents after and including the extent that had the problem: "prostrct remove <dbname> -a"
6. Add the AI extents back again: "prostrct add <dbname> addai.st"
7. Backup the database
8. Restart AI:  "rfutil <dbname> -C aimage begin"
9. Restart the database