Yo, i understand your frustration, but debuging by the “common way” is the first thing to do.
If your install worked before upgrading and no more after, it’s logical to think that there is somewhere a conflict or a missing piece of code.
Custom themes and plugins are mostly the culprit. JS sliders, plugs with text editors are also common sources of problems.
There is no universal answer. Each site is different, each problem too.
I recently get a blank page because of a missing > in one of my template loop !
I updated to 1.6.1 and all my pages disapeared and i had to recreate them one by one.
After 4 years of BP usage, it’s just an incident. But i understand, especially it it’s the first time you run such a trouble, how this can be annoying, for sure !
On this topic, you claim all “it’s no more working.” but no one said what he did, what theme he use and what type of install he manage. All these details are missing in this topic. And so far i know, nobody here is a soothsayer. I’m not.
Other common forum user behavior: no or less feedback when a solution is found. So coming here and saying “it’s not the problem” after an answer, is not fair. If it’s not the problem, why do you ask for help ? And if it’s the problem, why don’t you explain it ?
Pages are gone is not the probleme description, it’s the problem RESULT description.
A clearly explained problem brings to a clearly solution.
I don’t know what happens for you. I only try to help you with common questions intented to guide your debug search.
Let me suggest you that if you want to know what 1.6.1 did, go to the trac and compare the version changes. It’s very easy to find this information on the Trac. But you have to read the code.
If “it’s not the problem” with common guidance as read above, may i suggest you to activate the debug mode in wp-config file. Perhaps some warnings or server information will help you further.
Sorry it’s also a common help answer. And as i’m french, sorry for my poor english.