Why am i unable to choose the rquired material center during voucher entry?

If you are unable to choose the warehouse or material center at voucher entry, then there can be some possible reasons:
1.Fixed material center in POS configuration : If you have fixed the material center in POS configure then you will not able to change or choose another material center. To resolve the above issue, follow these steps:
Step 1: Go to administration section then click on configuration.
Step 2: Choose voucher series configuration and select the required voucher type.
Step 3: After select the voucher type, select series for it and then click on voucher configuration option.
Step 4: Click on configure advance POS option and select semi variable or variable in field type for material center then save the configuration.
2.Master control: If you have allowed one material center or disallow any material center in master control then you will not able to choose the desired warehouse at voucher entry. To resolve the above issue, follow these steps:
Step 1: Go to administration section then click on configuration.
Step 2: Choose voucher series configuration and select the required voucher type.
Step 3: After select the voucher type, select series for it and then click on master control and correct the configuration then save it.
3.Branch configuration : If you have logged for branch then you will able to choose or create invoice with only tagged material center in branch configuration. To resolve the above issue, follow these steps:
Step 1: Login the head office company 
Step 2: Go to administration section then click on configuration
Step 3: Choose features and option then select the enterprise feature.
Step 4: Click on multiple branch configuration and select the required branch
Step 5: correct material center tagging and save the branch configuration.
Note- Please take the latest backup before any process.