Wikidevi previously announced impending shutdown Oct 31st, but it is currently inaccessible as the certificate expired on 10/19/2019 and the site has a security policy called HTTP Strict Transport Security (HSTS) which prevents access by Firefox and Chrome.
Ray
Likely, the certificate is “bad” in some way.
No, it's an expired certificate:
NET::ERR_CERT_DATE_INVALID
Subject: wikidevi.com
Issuer: Let's Encrypt Authority X3
Expires on: Oct 19, 2019
Current date: Oct 23, 2019
I guess "bad in some way" includes "expired" 
it's out of date for a quick fix backdate you computers date
I have manages to force firefox to show the page
but i have to set a few setting & delete a file but it was pain full
but if firefox keeps going down hill like this much more i will be using something else soon
I did this to make it work
in (about:config), right-click, choose "New Integer", then provide the name "test.currentTimeOffsetSeconds" (no quotes) with a value of 11491200
set network.stricttransportsecurity.preloadlist to false
erased the browsers cache
closed it & deleted al l the copys of SiteSecurityServiceState.txt I found in mozilla folders
I'm not sure witch one's you need but after all of these i can now override & view the pages
Safari still allows you to add an Exception to view pages with expired certificate.