Hi Mavis,

An error 4102 is usually indicative of corrupted data. In your case, when you tried to post an order, the order header file was locked by some process and the posting was not successful.

There are many possibilities as to why this could have happened - one common reason would be that opportunistic locking is enabled somewhere where it should not be.

You likely will need to restore your data from a backup or have it repaired. You may be able to use the Integrity Check and Rebuild to fix it, depending on the type of errors.