This one has been driving me crazy and I've posted a couple places about it, but not here. I'm 99% sure this is not a CF problem per se, but something with isapi_redirect, IIS, Tomcat and maybe web.config.
Windows 2016 server, IIS 10 and Adobe ColdFusion 2018 using Tomcat. The server has about 8 sites on it and one site is getting intermittent 500 errors. All other sites remain up and responsive. Failed Request Tracing shows "Filter Error - Incorrect Function 0x1"
The site will come back up if you recycle the app pool for that site, or restart that site in IIS. I have the app pool set to recycle every 10 minutes for now to minimize downtime (which is now at about 4-6 times per day - could be mid day when presumed traffic is heaver than middle of the night - it doesn't seem to matter).
In March it was doing it frequently (once per day or more) and we recreated the site - new web root, new IIS config etc. same thing. I then noticed that the uptime on the server was several weeks, where normally it should reboot on every Sunday night and also pop a notification that updates were installed and a reboot is needed (neither of those happy anymore). Did the reboot and the site was fine - until 6/22. Then the 500s started again. I've scoured every log and there is no single event, template, or URL that I can see that causes it. Charlie has spent a bit of time working with us on this but we're still experiencing the errors. One thing I had done back in March was strip the web.config of the redirects - other than http to https - not sure if it was that or the reboot that gave us a few months respite.
Tomorrow in desperation I'll clone the site into a new directory, create a new IIS site and run wsconfig on it to see if that helps. Every time I now Google for this error I'm only getting my posts about it so for some reason I seem to be complete alone in this quagmire!