Solution 1These are the basic troubleshooting steps you need to follow to fix QuickBooks Java Error 1601. If the problem persists, select another solution to resolve it. The troubleshooting steps are as follows: -

• Firstly, open the RUN window
• Then type the command prompt in it and click on the Enter button
• The window of the command prompt opens up
• In this, type the exe/unreg and then enter
• A message box is shown on your screen
• This is the message that asks you for the confirmation
• So, provide the confirmation
• Again, open the RUN window
• Then open the command prompt and type exe/regserver
• Press the enter button to run the command
• Now in the confirmation window, provide the confirmation by clicking on the OK button
• In the end, you can easily download and update the software without any interruption.