Free updates for P3D4/5 are available
737-300 v.1.009
737-400 v.1.200
737-500 v.1.200
TO GET THE LATEST VERSION:
1. Turn OFF your antivirus including default Windows Defender. Why?
2. Make sure your simulator is not running.
3. Navigate Windows Start > Captain Sim > Update 737-300 [P3D4/5], run and follow the installer prompts.
4. Repeat step #3 for 737-400 and 737-500 Expansions if installed.
OR
1. Login to Your Profile, navigate: Product Name > Extended Download Service. YouTube
2. Download the full latest version of the product(s) to any folder on your computer.
3. Make sure your simulator is not running.
4. Run the installer .exe file(s) as Administrator and follow the installer(s) prompts.
NOTE: Backup your installed liveries and mods before installing.