Pay bill voucher is not opening how i can open it?

This is not the impression we want you to experience, khalid-mehmood. 

If you are referring to the Pay Bills button not working in the New Plus icon, then we have an ongoing investigation about this one. Our engineers are working together on the permanent fix on this issue. What we can do is to pay the bills by going to the Expenses menu. Then, choose Suppliers and click the Make Payment link to record bill payment.

Once done, I'd suggest reaching out to our Customer Support Team. They'll add you to the list of affected users and send you an email notification once there's an update on this issue. You may send a message via chat, call us at a time convenient to you, or we’ll get in touch with you instead. To ensure we address your concern, our representatives are available from 6:00 AM to 6:00 PM on weekdays and 6:00 AM - 3:00 PM on Saturdays, PST. Here's how:

1. Go to the Help menu at the upper right.
2. Select Contact Us.
3. Enter your concern.
4. Click Let’s talk.
5. Choose Get a callback. 
6. Type in your contact info.
7. Select Confirm my call.

Visit our QBO Help Articles page for more insights about running your business in your account.

The Community will always have your back if you have additional concerns about QuickBooks. Assistance is just one click away. You have a good one.