The error message “No valid source of supply could be found” in transaction code CK11N typically relates to the Material costing run in SAP. This error can occur when the system is unable to determine a valid source for the material cost calculation. To resolve this issue, you can take the following steps:

1. Check Material Master Data:

• Ensure that the material master data is correctly maintained in SAP. Verify the material’s procurement type, valuation class, and other relevant details.

1. Update Costing Views:

• In the material master data, check the costing views (e.g., standard price, moving average price) to make sure they are correctly set up and activated for the material.

1. Price Determination Strategy:

• Verify the price determination strategy for the material. This strategy determines how SAP calculates the material’s cost. Ensure that it is set up correctly in the material master and other relevant configuration settings.

1. Material Ledger Activation:

• Ensure that the Material Ledger is correctly activated for your company code and controlling area. Use transaction code CKMLCP to maintain the settings for Material Ledger.

1. Currency and Valuation Settings:

• Review the currency and valuation settings for your material and ensure that they match the requirements of your company code and financial accounting.

1. Check for Customization:

• If your organization has specific customization for costing processes, review them to ensure they are correctly configured.

1. Valid Costing Run Variants:

• In CK11N, make sure you are using valid costing run variants that match your requirements. These variants define how the costing run is executed.

1. Check for Price Changes:

• If there have been recent price changes or fluctuations in the material’s cost, these changes can affect the costing run. Review any changes and their timing.

1. Master Data Consistency:

• Ensure that master data, such as BOMs (Bill of Materials) and routing data, is consistent with the material master data. Inconsistent data can lead to costing errors.

1. Review Error Details:
   • Carefully review any additional error messages or warning messages that are provided by CK11N. They may contain specific information about what’s causing the issue.
2. SAP Notes and Documentation:
   • Check SAP documentation and relevant SAP Notes for your specific SAP version and industry. There may be specific notes or recommendations addressing this error in CK11N.

If you have followed these steps and are still encountering the error in CK11N, consider involving your SAP system administrator or a consultant with expertise in SAP Material Ledger and Costing. They can help troubleshoot and resolve the issue, especially if it involves complex configurations or customizations in your SAP system.