If you cannot install ES then enhanced search will not work.
ES 7 install, but basically the same for 8 and 9.
XF does have a limited return window (I think)
How To Install Elasticsearch 7.x for Xenforo
This is tutorial for installing (not upgrading)
elasticsearch 7 on centos.
If I am missing something, please post here.
Delete first old one if you have installed and install fresh new one elasticsearch v7
Installing elasticsearch 7
Code:
rpm --import https://artifacts.elastic.co/GPG-KEY-elasticsearch
Code:
nano /etc/yum.repos.d/elasticsearch.repo
insert this:
Code:
[elasticsearch]
name=Elasticsearch repository for 7.x packages...