Error while testing void (purchasecorrection)

I'm getting an unknown error on a void (purchasecorrection) test transaction.  Below is the payment transaction, the successful response, then the void request followed by the void error. What is the error? This is from a test suite that has run successfully in the past.

Bill 

<request>
<store_id>monca01472</store_id>
<api_token>y1gRdLhsRT8c9ITKgVhZ</api_token>
<efpid>064131021078000001</efpid>
<res_purchase_cc>
<data_key>XXaCsquWRak6sib0ncOItZv24</data_key>
<order_id>064131021078000001</order_id>
<cust_id>25</cust_id>
<amount>21.00</amount>
<crypt_type>7</crypt_type>
<cust_info>
<billing>
<first_name>Thomas</first_name>
<last_name>Cortez</last_name>
<company_name></company_name>
<address>791 Tillman St.</address>
<city>Fort Worth</city>
<province>TX</province>
<postal_code>76101</postal_code>
<country></country>
<phone_number>8174467773</phone_number>
<fax></fax>
<tax1></tax1>
<tax2></tax2>
<tax3></tax3>
<shipping_cost></shipping_cost>
</billing>
<email>islezakp@example.com</email>
<instructions>none</instructions>
</cust_info>
</res_purchase_cc>
</request>

<response>
<receipt>
<DataKey>XXaCsquWRak6sib0ncOItZv24</DataKey>
<ReceiptId>064131021078000001</ReceiptId>
<ReferenceNum>660158180011190020</ReferenceNum>
<ResponseCode>027</ResponseCode>
<ISO>01</ISO>
<AuthCode>538565</AuthCode>
<Message>APPROVED * =</Message>
<TransTime>15:43:30</TransTime>
<TransDate>2020-04-27</TransDate>
<TransType>00</TransType>
<Complete>true</Complete>
<TransAmount>21.00</TransAmount>
<CardType>M</CardType>
<TransID>2421-0_15</TransID>
<TimedOut>false</TimedOut>
<CorporateCard>false</CorporateCard>
<RecurSuccess>null</RecurSuccess>
<AvsResultCode>null</AvsResultCode>
<CvdResultCode>null</CvdResultCode>
<ResSuccess>true</ResSuccess>
<PaymentType>cc</PaymentType>
<IsVisaDebit>false</IsVisaDebit>
<ResolveData>
<cust_id>25</cust_id>
<phone>8174467773</phone>
<email>islezakp@billmax.com</email>
<note/>
<expdate>2208</expdate>
<masked_pan>5454***5454</masked_pan>
<crypt_type>7</crypt_type>
<avs_street_number/>
<avs_street_name/>
<avs_zipcode/>
</ResolveData>
<efpid>064131021078000001</efpid>
</receipt>
</response>

<request>
<store_id>monca01472</store_id>
<api_token>y1gRdLhsRT8c9ITKgVhZ</api_token>
<efpid>064131021078000002</efpid>
<purchasecorrection>
<data_key>XXaCsquWRak6sib0ncOItZv24</data_key>
<order_id>064131021078000001</order_id>
<txn_number>2421-0_15</txn_number>
<crypt_type>7</crypt_type>
</purchasecorrection>
</request>

<response>
<receipt>
<ReceiptId>null</ReceiptId>
<ReferenceNum>null</ReferenceNum>
<ResponseCode>null</ResponseCode>
<ISO>null</ISO>
<AuthCode>null</AuthCode>
<TransTime>null</TransTime>
<TransDate>null</TransDate>
<TransType>null</TransType>
<Complete>false</Complete>
<Message>Exception : null</Message>
<TransAmount>null</TransAmount>
<CardType>null</CardType>
<TransID>null</TransID>
<TimedOut>false</TimedOut>
<BankTotals>null</BankTotals>
<Ticket>null</Ticket>
<IsVisaDebit>false</IsVisaDebit>
<efpid>064131021078000002</efpid>
</receipt>
</response>