Fatal error: Allowed memory size..
Fatal error: Allowed memory size of 8388608 bytes exhausted..
Textpattern’s memory usage is quite low – usually no more than a couple of megabytes.
Unless your server admin has set the PHP memory limit far too low — unlikely, but not impossible — the cause is probably a plugin. Some older archive page plugins work by loading all articles into memory at once. This could easily exhaust the available memory if you have a large number of articles.
Disable your plugins one by one, until you find the culprit. If the cause is indeed a plugin, we suggest contacting its author about the problem.