Here I re-re-re-re-re-repeat myself on this forum: Apache is notorious for running at all costs.
[I've said it dozens of times and will probably say it a dozen more]
Apache will do everything possible to run with a config that would otherwise be rejected by almost any other web server.
Errors will always creep into things over time and repeated manual modification - this is normal; as is with just about everything else in life.
Overlooking those errors is not; apache, although with the best of intentions, seems to look the other way a bit too much at times. And this may be one of those times.
Please start by checking your apache config with: apachectl -S