404 after trying to setup https, but usual solutions don’t work

I have tried to setup https on unibikenederland.nl by following method 2 in this tutorial. After step 1 where it says to change the wordpress adress and site adress (general settings) from http to https, my /wp-admin returned a 404 error.

At this stage, my page did still work. Some media did not show as they did not use https yet. As far as I understand that was to be expected at this point. However, while trying to solve the issue with below steps I at some point caused the homepage to also stop working. Since I was not monitoring the homepage because it worked fine, I don’t know at which step this changed. The homepage now says I need to upload an index.html file as if the index.php file was not there (it is there).

I have searched the internet and WordPress support pages, and did (in this order):
– Followed step 2 in the tutorial to see if furher along I could access wp-admin again. Next step involved adding some lines in .htaccess. When this did not work I stopped following the tutorial and started troubleshooting based on other sources.
– Try set page locations manual in wp-admin
– Try set page location manual in theme’s functions.php
– Set page locations manual in phpMyAdmin
– Delete .htaccess temporarily
– Rename theme (oceanwp) temporarily so it is not used
– Try turn off ‘secure SSL’ and ‘Force SSL’ in hosts domain management page

Thank you in advance, for supporting me and hence saving me several days of creating content, changing lay-out, etc.

• This topic was modified 5 years, 8 months ago by srgtfoxhill.
• This topic was modified 5 years, 8 months ago by srgtfoxhill.

The page I need help with: [log in to see the link]