I am getting a blank page with one of your extensions

Alternative error message: "Exception printing is disabled"
Alternative error message: "500 Internal Server Error"

Steps to figure out the actual error message:

In the file index.php of Magento (located inside the root directory of Magento), look for:

if (isset($_SERVER['MAGE_IS_DEVELOPER_MODE'])) {
    Mage::setIsDeveloperMode(true);
}

#ini_set('display_errors', 1);

Replace with:

#if (isset($_SERVER['MAGE_IS_DEVELOPER_MODE'])) {
    Mage::setIsDeveloperMode(true);
#}

ini_set('display_errors', 1);

Then open the page again that is blank. You'll see the error description now. REVERT the changes in index.php after retrieving the error message.