Problem with cached pages

Description

PHP Error (logged by watchdog):

warning: Compilation failed: characters with values > 255 are not yet supported in classes at offset 143
in
/var/www/html/XXXXXXX/XXXX/modules/search.module
in line
265.

(the photos of the site are attached)

Then I try to access http://www.mywebsite.com/mydrupal and he returns only a lot of strange characters.
I think this problem is releated with the cache, because if I turn it off, the problem desapear. I had already even tryed installing FSCache, but the error keep apearing.