The error mainly occurs when Windows cannot verify the digital signature certificate for QuickBooks. So, to fix this issue, try installing the digital signature certificate using the following steps:
Close QuickBooks.
Navigate to C:\Program Files\Intuit\QuickBooks.
Find the QBW32.exe file and select Properties.
Go to the Digital Signature tab.
Scroll through the Signature list and select Intuit, Inc.
Click Details and then open the Digital Signature Details window.
Click View Certificate.
Next, in the Certificate window, select Install Certificate.
Click Next and then Finish.
Restart your computer.
Open QuickBooks.
Download the latest update.
Give a call at our helpline number (1800-579-9430) and connect with the QuickBooks technical support team if you have any doubts about QuickBooks error 15311.