Tax change when edit product

Hello there, Please Help me in Tax.

Once i added Product in sale order , Purchase order or any other form with tax and when i Update tax then it change a garbage value or default value of tax.
Ex.
product name : Test product
tax :9 / 9 % (total 18%)
Price: 1
total : 1.18

When i edit this change tax to 12 %(6% 6%) and save form then following thing Will happed

product name : Test product
tax :99999.9999 / 999999.9999 % (total 18%)
Price: 1
total : 1.12
Please Provide solution for that.

@sagarkumar

There are only 3 place which the TAX is being affected you need to review and correct it from there.

  1. Globar VAT update
    a. Home → Setup → Admin Tools, You will see the Global VAT update as shown below:

  2. Setting up the Tax
    a. Home → Setup → Dictionary setup, Need to check carefully as shown below:

  1. Accounting → Show Tutorial this is just the same as above, Just Check it carefully as shown below:

Then no worries as simple as that.