Hi Fillip, not is not a cache issue.
So I explain you what I have understand in this days.
If you go here
Tag - Sigaretta Elettronica Forum
The problem is that many tags aren't founded and make go in crash the site.
I thought were only the search of tags the sistem don't found in the memory that was giving errors, but in the end I have understand that also those that are in the memory generate an error.
Searching the tag "e-liquid" you can see what happen:
vBulletin Database Error
and if I search the tag for example "sarà" it make a strange error.
The site crash with a database error
The link of the tag in the bar upside is correct and it seems that keep the utf8 because is visualized in this way:
PHP:
http://www.sigarettaelettronicaforum.com/tags/sarà
But if I copy the link and I try to past it here like text in the post, it write me the link in this other way:
PHP:
http://www.sigarettaelettronicaforum.com/tags/sar%C3%A0.html
And also the error you can see when the page go in crash is this:
PHP:
Database error in vBulletin 2.0.32:
Invalid SQL:
SELECT tagtext AS id FROM vb4_tag WHERE tagtext REGEXP "^(&[\#\da-z]*;|[^a-z\d])*(&[\#\da-z]*;|[^a-z\d])*[s][a]r%C3%A0(&[\#\da-z]*;|[^a-z\d])*(&[\#\da-z]*;|[^a-z\d])*$" ORDER BY LENGTH(tagtext) LIMIT 1;
MySQL Error : Got error 'invalid UTF-8 string at offset 45' from regexp
Error Number : 1139
Request Date : Tuesday, May 31st 2016 @ 11:41:21 AM
Error Date : Tuesday, May 31st 2016 @ 11:41:21 AM
Script : http://www.sigarettaelettronicaforum.com/tags/sar%C3%A0.html
Referrer : http://www.sigarettaelettronicaforum.com/tags/
IP Address : 93.58.31.180
Username : N/A
Classname : DBSEO_Database_MySQLi
MySQL Version :
look the link inside.
Then I have also noted that all the thread with this symbol "%" in the title, the link aren't reachable and if I try to send a post with this symbol the thread crash the system and the page is also unreachable.