Symptoms
The IDOCs that are received by the WCF-SAP adapter from multibyte character set (MBCS) SAP systems have an empty data segment (SDATA field).
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Resolution
This problem is fixed in the following cumulative update for BizTalk Server:
Cumulative Update 5 for BizTalk Server 2020
References
For information about the service packs and cumulative update list for BizTalk Server, see the following article in the Microsoft Knowledge Base:
2555976 Service pack and cumulative update list for BizTalk Server
For more information about BizTalk Server hotfixes, see the following article in the Microsoft Knowledge Base:
2003907 Information about BizTalk hotfixes and Cumulative Update support