Message type: E = Error
Message class:  HRGB_GBSXP - Message for GBSXP 
Message number: 644
Message text: SPL Booking Request: T5GPBS_ALL constant missing (Keys &1)
Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of messages in the SAP system have a message text, however this is frequently insufficient to comprehend or resolve the problem.
To make things easier, more detailed information is frequently added to describe the issue, how to fix it, and the necessary steps or configuration modifications.
Unfortunately, there isn't any extra information in this error notice.
First, use our AnswerBot below to get a possible cause and solution (requires a premium subscription).
Also, review the in-depth Common Questions & Answers listed below; you could discover a solution there or be able to connect with others who have faced similar challenges.
You can also try searching the SAP support portal (support.sap.com) but you need a special user ID to access it. It is possible that an SAP support note exists that provides additional details about the mistake or even steps for fixing it.
The SAP error message HRGB_GBSXP644 indicates that there is a missing constant in the configuration related to the SPL (Sanctioned Party List) booking request. Specifically, the message states that the constant T5GPBS_ALL is missing, which is likely a configuration or master data issue.
Cause: Missing Configuration: The constant T5GPBS_ALL is not defined in the system. This could be due to a missing entry in the relevant configuration tables or a failure to transport necessary configuration from a development environment to production. Data Inconsistency: There may be inconsistencies in the data that are causing the system to look for a constant that does not exist. Authorization Issues: Sometimes, the user may not have the necessary authorizations to access certain constants or configuration settings.
Solution: Check Configuration: Go to the relevant configuration area in SAP (usually under SPRO) and check if the constant T5GPBS_ALL is defined. If it is missing, you may need to create it or transport it from
 Get instant SAP help. Sign up for our Free Essentials Plan.
Get instant SAP help. Sign up for our Free Essentials Plan. 
HRGB_GBSXP643 Statutory Pay Entitlement Warning: Contractors have no entitlement
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
HRGB_GBSXP642 Statutory Leave Entitlement Warning: Agency Staff have no entitlement
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
HRGB_GBSXP645 SPL Booking Request: T5GPBS_ALL constant &1 not valid (Keys &2)
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
HRGB_GBSXP646 SHPP Error: KIT days are not allowed
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
Click on this link to search all SAP messages.