Symptoms
When you use Microsoft BizTalk Server to receive a compressed Applicability Statement 2 (AS2) message, an error message that resembles the following might be logged in the Application log:
Event Type: ErrorEvent Source: BizTalk Server 2009 EDIEvent Category: NoneEvent ID: 8133Description:The AS2 Decoder encountered an exception during processing. Details of the message and exception are as follows: AS2-From:"<AS2-From party>" AS2-To:"<AS2-To party>" MessageID:"<Message ID>" MessageType: "unknown" Exception:"Decompression failed while processing a compressed AS2 message. Error: Invalid Adler32 checksum encountered."
Note The event source value may vary depending on what version of BizTalk Server you use.
Cause
This issue occurs because the Adler32 checksum value is stored separately in two chunks when you receive a compressed AS2 message. Therefore, BizTalk Server does not read the value correctly.
Resolution
Cumulative update information
BizTalk Server 2006 R2The hotfix that resolves this issue is included in cumulative update package 4 for BizTalk Server 2006 R2 SP1. For more information about how to obtain the cumulative update package, click the following article number to view the article in the Microsoft Knowledge Base:2682056Cumulative update package 4 for BizTalk Server 2006 R2 SP1BizTalk Server 2010For more information about how to obtain the cumulative update package, click the following article number to view the article in the Microsoft Knowledge Base:
2497789 Cumulative update package 1 for BizTalk 2010 BizTalk Server 2009The hotfix that resolves this issue is included in cumulative update package 2 for BizTalk Server 2009. For more information about how to obtain the cumulative update package, click the following article number to view the article in the Microsoft Knowledge Base:
2497794 Cumulative update package 2 for BizTalk Server 2009
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
References
For more information about BizTalk Server hotfixes, click the following article number to view the article in the Microsoft Knowledge Base:
2003907 Information about BizTalk Server hotfixesFor more information about the "Invalid Adler32 checksum encountered" error message, visit the following MSDN website:
General information about the "Invalid Adler32 checksum encountered" error message
