To enter the license key, go to menu Help – About (or File menu – Account – About), and click the Enter Product key button. Insert the license key and click the Register button.

You can compare two projects by going to menu Report and press on Compare button.
For more information, please read the following articles:
https://www.projectplan365.com/training/lesson-10-compare-plans/
https://www.projectplan365.com/articles/compare/

To assign an email address to a Project Viewer subscription, please Sign In with your email and password in our Portal page: https://www.projectplan365.com/ups/Account/SignIn , click on the “Assign” button, type the email address of the new user and click on the “Add” button.

The Project Viewer 365 perpetual license can be used on both Mac and Windows devices. You need to download the Project Viewer 365 application from the following link: https://projectviewercentral.com/download and to register the license key received when purchasing the license.

Our sales are final because we offer 30 days of trial version of the fully functional product – see below link, which is displayed when placing the order.
http://www.projectviewercentral.com/returnpolicy/

No need to cancel your trial. You won’t be charged after your trial ends.

If you want to unsubscribe or cancel automatic purchase/renewal please follow the instructions from the link below:
https://support.apple.com/en-us/HT202039

Based on the error looks like a temporary issue with Pay Pal service.
Please try again in 1 hour.

Please know that the Project Viewer 365 perpetual license is available only for Windows and Mac devices. If you want to use the Project Viewer 365 application on your iOS device, you need to start an Advanced Viewer or Complete Editor subscription from App Store.

The Project Viewer 365 perpetual license is available only for Windows and Mac devices. If you want to use the Project Viewer 365 application on your iOS or Android device, you will need to purchase a subscription from Google Play/Apple Store.

You can achieve this by following the steps below:
First solution
1.Go to menu tab Project and select Filter button
2.Then select filter by Task Range
3.It will appear a dialog. In the first textbox put 5 and in the second one 25. Press ok.

Second solution
4.Go to menu tab Project and select AutoFilter button
5.In task name column, create a filter to show only tasks from 5 to 25.

6.Then in Print Preview dialog you will see only tasks from 5 to 25 and you can print them.

To unhide a column you need to insert again that column.
Please read the article below:

https://www.projectplan365.com/articles/inserthidemove-column/

First please check if you are signed in on App store with the account used to buy the subscription (to find this info, open Settings, Click on iTunes & AppStore and on Apple ID check your email address).
then
Go inside application and in Purchase Additional Functionalities dialog Press Restore Advanced Viewer Subscription
Wait confirmation message
Restart application
After restart, application will be unlock.

Yes, Project Viewer 365 for MAC utilize iCloud Drive.