Client Modifiable issue in T-Code VK0A

Hi Experts,

I am facing the Problem in Client setting in Production server.

client is not modifiable and no changes allows in SCC4.

but when i execute the T-Code VKOA and going to the "903 Sales org./Distr. Chl/AcctAsgnmt/Acct key"

it does not restrict and open in edit mode.

but in same case in Quality server its restrict.

Client setting is same in PRD & QTY server.

in scc4 and se03

Please suggest.

REgards,

Vivek