Lockbox Post Processing Error - Customer * is not defined in company code

Hello SAP Guru's,

I am facing problem with postprocessing of Lockbox. During the postprocess, I get error message that states Customer * is not defined in company code. I have checked configuration and all is fine. Also, I checked Customer master data and did not any find any issue. Lockbox file is working properly in production clien in 4.7. I am only facing this problem with Dev box of ECC 6.06.

Please help.

Thanks