really need some help with posting: Illegal offset type

I installed a wordpress blog here

https://splitlipderby.com/

Ive installed them before and never had a problem.

Just so you know what I have tried to reinstall the wordpress, I have tried to delete the cache.php file and I have tried to swich the admin username with no luck.

I was getting this error.

Warning: Illegal offset type in /home/splitlip/public_html/wp-includes/cache.php on line 125

So after resinstalling didnt work, changing theme, replacing the cache.php

I asked my host

They seemed to remove the error.

Now when I post, the posts never seem to get through.

It keeps them as draft and when it posts…
it just says not found…

any ideas?