This solution has worked for me. After running some obscure portals found on GitHub, I began receiving the error "Error activating portal" when attempting to activate any previously working portals.
Access /www
Remove all contents excluding the captiveportal directory or its contents.
Access /root/portals.
Remove all existing portals you may have added.
Prepare to transfer original portal files from your host to the Pineapple.
In each portal directory, for example facebook-login, remove the enable and disable files.
Re-transfer each of the evil portal directories to the /root/portals path.
Access Pineapple Evil Portal module and attempt to activate.
TLDR: On the pineapple, remove everything from the www folder but the captiveportal folder. Then delete all files in the /root/portals. In your Kleo EvilPortal repo clone, delete the enable/disable files from each of the portal folders and re-add them to the /root/portals path.
Hope this helps, it has worked for me each time I have tried using a non-working evil portal.
Notes: Portals I tested and found not working. These resulted in errors when activating other portals.
JonnyBanana/Netflix_EVIL_PORTAL
gscamelo/evilportals Microsoft SSO Evil Portal
LuemmelSec/evilportals ADFS Evil Portal