OM extension not working when sales order revision

Summary:

Sales order created and we do revision of sales order and some changes in sales order and order submit time below error showing:

"After sales order revision submit time error : You can't use the applyHold method in an order management extension for a change order or for a sales order that you already submitted to fulfillment. (FOM-4515773)"

OM Extension code as below:

import oracle.apps.scm.doo.common.extensions.ValidationException
import oracle.apps.scm.doo.common.extensions.Message

// Run the extension only on sales orders that are on hold.
def lines = header.getAttribute("Lines")

while (lines.hasNext()) {
def line = lines.next()