The software is showing star symbols or random numbers instead of some invoice details like quantity, rate etc. What could be the reason and how to resolve it?

In case in invoice print,if it is showing quantity,rate or any other amount details as star,it means in invoice format number of characters to be printed as exceeded while voucher entry.You can configure number of characters to be printed in standard as given steps
 Step 1: Go to Administration and click on configuration tab.
 Step 2: Click on Invoice / Document Printing and choose Standard.
 Step 3: Choose the voucher type (such as sale)
 Step 4: Now in body option box,select self configured
 Step 5: Now you can adjust number of characters for quantity,rate or tax as per and adjust it from another fields as it width should not exceed in limit shown there like 136
 If you wants to correct issue of quantity rate and other fields showing in star,you need to check it in advanced format,follow these steps 
 Step 1: Go to Administration and click on configuration tab. 
 Step 2: Click on Invoice / Document Printing and choose Advanced. 
 Step 3: After selecting the voucher type that you want to customize (for example, sale or purchase, etc), you will see the name of your format below it. 
 Step 4: Clicking on the format name will allow you to customize different parts of the printing format, such as the header, body, & footer etc. 
 Step 5: In advance format we have give layouts such as A5, slip 3 inch, slip 4 inch. further you can also customize it as per your paper layout.
 Step 6:Now if the field is in header,body or footer,select and on particular line,specify charcters for field and adjust in another fields 
 Note:Design or customise format as per your needs and other changes,it is on chageable basis depending upon the needs in invoice format