DevMode Class 'Exception\RuntimeException' not found We started getting this error inconsistently on our site, and now it's constant unless we turn devMode off. We have no idea what may be causing it, but it only happens on one page. With devMode turned off, this page loads as intended with no issues. Here's a stack trace of what's coming through:

Class 'Exception\RuntimeException' not found
/craft/app/framework/vendors/zend-escaper/Escaper.php(321)
/craft/app/framework/vendors/zend-escaper/Escaper.php(182): Escaper-&gt;toUtf8("[11:24:06.471][trace][system.db.CDbCommand] Executing SQL: UPDAT...")
/craft/app/framework/web/helpers/CJavaScript.php(35): Escaper-&gt;escapeJs("[11:24:06.471][trace][system.db.CDbCommand] Executing SQL: UPDAT...")
/craft/app/helpers/LoggingHelper.php(51): CJavaScript::quote("[11:24:06.471][trace][system.db.CDbCommand] Executing SQL: UPDAT...")
/craft/app/templates/logging/log-firebug.php(46): Craft\LoggingHelper::processFireBugLogEntry("trace", "11:24:06.471", "system.db.CDbCommand", "Executing SQL: UPDATE `craft_budhub_spend_analytics` SET `id`=:y...", ...)
/craft/app/framework/logging/CWebLogRoute.php(52): Craft\WebLogRoute-&gt;render("log", array(array("Loading "cache" application component in /var/www/thisisbud.dev/...", "trace", "system.CModule", 1499945046.3493, ...), array("Loading "path" application component in /var/www/thisisbud.dev/c...", "trace", "system.CModule", 1499945046.3495, ...), array("Loading "request" application component in /var/www/thisisbud.de...", "trace", "system.CModule", 1499945046.3497, ...), array("Serving "usePathInfo" from cache in /var/www/thisisbud.dev/craft...", "trace", "system.caching.Craft\FileCache", 1499945046.3501, ...), ...))
/craft/app/framework/logging/CLogRoute.php(104): CWebLogRoute-&gt;processLogs(array(array("$_COOKIE=array ( 'ccc7c40e11a9bcf94cb9cc672f7748a0username' =&gt;...", "info", "application", 1499945046.3467), array("Loading "cache" application component in /var/www/thisisbud.dev/...", "trace", "system.CModule", 1499945046.3493, ...), array("Loading "path" application component in /var/www/thisisbud.dev/c...", "trace", "system.CModule", 1499945046.3495, ...), array("Loading "request" application component in /var/www/thisisbud.de...", "trace", "system.CModule", 1499945046.3497, ...), ...))


A few points that may help:


We are accessing and saving (encrypted) binary data to the DB, though we do this elsewhere on the site without issue.
The twig being loaded loads other pages too, which all run fine seperately
DevMode turned off, we can't see anything that's not working, but with devMode on, it's impossible to get past said error.


We've been wrestling with this for a while without any luck. Any help would be greatly appreciated!
Definitely agree with the comments that you should enable devMode from day one when working on a project. In addition, coding defensively can help avoid common frontend errors as well.

There's more on this topic in the article Handling Errors Gracefully in Craft CMS