Explaindio is a fairly new software and norton is not yet aware of the codes from the program. So by default, to protect your computer, norton would inform you that this software is a potential risk to your computer.
That is a term called "False positives" where in norton thinks that the file is a virus where in fact it isn't. To work around this issue:
1) Disable Auto protect from your Norton Antivirus software.
2) Download and install Explaindio video creator.
3) Resume your Norton antivirus software.