Thread:Project:Support desk/Problem Upgrading from 1.16.1 to 1.18.3/reply (4)

If ProfilerStub.php is not included in 1.18.3, you can remove it.

But I think the root of your problem might be somewhere else: See if you have a file called StartProfiler.php (or somehow like that) in the root directory of your wiki installation. If you have, this file is outdated and might likely cause the error.

Remove it or check the new example file, which comes with MW 1.18.3 to see how you must adjust this profiling file so that it works again.