ORA-06508

U:Error in Routine WSH_USA_ACTIONS_PVT.Split_Records_Int, Oracle Error - -6508
ORA-06508: PL/SQL: could not find program unit being called

As per ITS log file the issue is arising when a call to package WSH_DELIVERY_DETAIL_INV is being made.
Patch 8294645:R12.WSH.B is the resolution of the issue.
Reference: Bug 9802248 - INTERFACE TRIP STOP SRS IS COMPLETED WITH WARNING

If the above does not resolve the issue, please try the following:
Drop packages

The suggestion is to have your DBA complete the following
Perform the following steps as an Action to resolve the issue.

1. drop package apps.WSH_DELIVERY_DETAILS_INV;
$WSH_TOP/patch/115/sql/@WSHDDICS.pls;
$WSH_TOP/patch/115/sql/@WSHDDICB.pls;

2. Regenerate Forms.

Once the above is completed, the error message should be resolved.

If the above does not resolve the issue, per Development's update on Internal Bug 8294645:  "As a workaround patch 8294645:R12.WSH.B has been created. Root cause is being worked in bug 8306160 and Bug 8306160 says: This is PLSQL bug 8357541"

1. Download and review the readme and pre-requisites for Patch:8357541 , appropriate for your database release.

2. Ensure that you have taken a backup of your system before applying the recommended patch.

3. Apply the patch in a test environment.

4. Retest the issue.

5. Migrate the solution as appropriate to other environments.