What are some reasons Selenium wouldn’t find an Element?

I’m writing an automated test for a Web-based application that’s coded in JavaScript and uses the Dojo framework. I can find the elements I want the bot to find in Developer Tools using well-defined XPATHS, but the automated test fails to find the text the XPATH leads to.

My test code looks something like this:

if verified:
     verify_detail.set_pass()
else:
     raise AssertionError("Cannot verify detail. Text did not match expected value.")

And the text I’m looking for on the UI isn’t misspelled in the config file.

Anyone else have this problem? XPATH works in Developer Tools but fails when the test is run.