After the scan has ran you will see a report status of either “Good” or “Notice”. Scan checks with a “Notice” will not prevent the build from running, however if you do run into anypackage build issues then its possible the “Notice” should be investigated. If you receive a notice and you are not sure how to proceed, we recommend proceeding with the noticeand see if the package builds. Below is a list of the scanner sections with details on how to proceed.

SETUP

The Setup section show various data about the server and WordPress environments.

• System:The System area consists of various test for your Web Server, PHP and hosting environment.If you run into an issue in this section, there should be details how how to properlyproceed with each notice.
• WordPress:This section tests for various WordPress setup issues and alerts you if anything is found.

ARCHIVE

• SIZE CHECKS
  If the scanner shows warnings for larger files/databases you might have issues if you’re on a shared budget host. Having access to your ownserver or VPS you should be able to easily follow the instructions for timeouts and get Duplicator runningwithout any issues. With Duplicator Pro multi-threaded support for larger sites can help improve the overall build process.

  Budget Hosts:Its possible that you may run into timeout issues more so with Duplicator Lite on a budget host as it has a single threaded process. If the host kills the PHPprocess in the middle of trying to zip up your files then it will not be able to archive the file.Duplicator Pro has a mutli-threaded process that allows forlarger sites but can still run into issues with sites above 2GB depending on your hosting provider and their limitations on PHP processes.

• NAME/READ CHECKS
  If you receive a ‘Notice’ status on the [Archive > Files > Invalid Names] line and the full path to the file is below 256 characters you should be good.A warning is shown at 250 characters to bring attention to the issue and warn users that their might be an issue if the path continues to grow.

  Basically is what happens with zip programs like winrar/winzip and even the PHP library used to extract the files is that they work fine to package up the files,however when they are extracted on some operating systems such as windows they run into a path limit. One way to validate if the zip file is corrupt or unusablewhen extracted to its new destination, is to try and extract it with a program like winrar/winzip and it will throw errors about file length issues if they are present.

Also see:
What can I do for issues with migrating a large site?
Recommended hosting providers for Duplicator?