Message type: E = Error
Message class:  SLS_LORD - Lean Order Prozess 
Message number: 306
Message text: Number range number &1 of alt. order type &2 is different than &3
You want to set an alternative order type for a sales document that has
already been saved. In this case, the number range number of the number
range object RV_BELEG of the alternative order type cannot be different
than that of the current order type. However, the
&V4& number range number of the &V1& alternative order type &V2& is
different  than the number range number of the &V3& current order type.
The system does not allow the alternative order type.
Choose a valid alternative order type.
The system issues an error message and will not allow you to continue with this transaction until the error is resolved.
Error message extract from SAP system. Copyright SAP SE.
The SAP error message SLS_LORD306 indicates that there is a mismatch in the number range settings for an alternative order type. Specifically, it suggests that the number range assigned to the alternative order type does not match the expected number range.
Cause: This error typically occurs due to one of the following reasons: Configuration Issue: The number range for the alternative order type has been incorrectly configured in the system. Inconsistent Data: There may be inconsistencies in the data where the system is trying to use a number range that is not aligned with the defined settings for the order type. Custom Development: If there are custom developments or enhancements in the system, they might be causing the number range to be referenced incorrectly.
Solution: To resolve the SLS_LORD306 error, you can follow these steps: Check Number Range Configuration: Go to the transaction code SNRO (Number Range Objects). Find the relevant number range object associated with the alternative order type. Verify
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