Explanation
When the number sequence in Dynamics AX has reached the highest number, an error message will occur,
"number sequence has been exceeded." This can occur with any process done in Dynamics AX that uses a number sequence. The example below occurred when a sales order was trying to be confirmed. Due to the number sequence reaching the highest number, the system will not allow the sales order conformation to be completed.
To fix the issue, you will first need to look up the number sequence that will need to be changed.
1. Go to Accounts receivables> Accounts Receivables Parameters
2. Look for Conformation
3. Right-click view details on number sequence code (Sales_31)
4. Click edit
5. Add another # in an alphanumeric segment that will extend the value field
6. Add another 9 in the largest field
7. Click edit again to save
Reference: https://stoneridgesoftware.com/how-to-resolve-number-sequence-exceeded-error-in-dynamics-ax/