If you have recently upgraded your Macs operating system to MacOS Catalina, you may find that when you next launch Blocs, you will be prompted to enter your license number again in order to activate the application.
Why this happened
Although Blocs had previously been activated on your Mac, part of the local registry that is created when you register Blocs is no longer valid under MacOS Catalina due to new security measures. This means you will need to activate the Blocs application again in order to create this local registry file.
At this point you may face one of the following problems. You don’t have your license number or your license number is running at its limit and cannot be used again.
The solution to this problem is relatively straightforward.
1. Start the Blocs application and ignore the license input dialog that is initially shown.
2. Navigate to Blocs > Preferences… from the main window menu.
3. When the preferences window appears, navigate to the tab labelled License and Left Click it. This will reveal a pane that contains two text fields, one of them should still contain your Blocs license number.
4. Copy the license number from within the field labelled License Number by selecting the entire text string and using the keyboard shortcut ⌘+C. Now paste your license number into a blank text document for future reference using the keyboard shortcut ⌘+V.
5. Now Left Click the button labelled Deactivate License that is located below the text input fields on the preferences license pane. This will reset your license activations, allowing you to use your license number again.
6. Return to the license input dialog that is shown when you first start Blocs and input your license number that you copied in step 4. Your copy of Blocs should now activate and allow you to use the full version of Blocs.