Dear sir I am using quick book software from last 3 months now quick book software is not allowing me to create any new invoices.

Welcome to the Community, @hireusfreelancer. Sometimes, your default browser holds too much cache and temporary internet files that causing QuickBooks to behave unexpectedly. 

To confirm, log in to Quickbooks using a private or incognito window by opening any regular browser, then follow these shortcut keys below: 

• Chrome simply press Ctrl + Shift + N.
• Mozilla Firefox and Internet Explorer, press Ctrl + Shift + P.
• Safari, press Command + Shift + N. Make sure you're using the latest version.

If you're able to create an invoice successfully, that means you're experiencing a browser-related issue that can be resolved by doing a few basic troubleshooting steps. I'd suggest you follow the steps to clear your browsing data. Otherwise, try using another supported, up-to-date browser. 

Let me know if there's anything else that you need help with. We're always delighted to provide our utmost assistance. 

@hireusfreelancer 

What really happens when you try to create a new Invoice for your customers?

To create an Invoice:

From the left Dashboard > Select "+ New" > Click Invoice under Customers