Please confirm whether the launch executable file is located in the C:\Program Files.
Check the below instructions : 

1. On the Affinity download page, select the option that has “EXE” below it.

2. During the installation process, you will be prompted to choose a location.
The default location is the C drive, and the .exe file will be installed in the following directory: C:\Program Files\Affinity\Designer 2.

3. Next, open Cartoon Animator 5, go to Edit > Preferences.

4. Click the folder icon, then navigate to C:\Program Files\Affinity\Designer 2 to find “Designer.exe”. Once found, select it and press Open.

5. After setting it up, click “Create Character” > Human Template.
If this is the first time you launch Affinity, it may ask you to log in with your Affinity account.
Once logged in, you will successfully import the Human Template.