Customized ESS not remain after performed an upgrade from EP6.0 to EP7.0

Dear all,

My client is having this problem where they upgrade their EP6.0 to EP7.0 and all their customized ESS become the standard ESS. As far as i understand, we need to re-implement modifications for the New track. (pls correct me if i am wrong). As told by my client, the old Track which contains those customized ESS has been corrupted.. Is there any way i can save the track back or by any other means i can get back the customized ESS source? (they are now having 2 EP in their development server, one is EP6 one is EP7) Thank you!

Regards,

Jo