AH00708: Cannot open data file


I have a fedora28 system with httpd-2.4.34-3.fc28.x86_64 and having a
problem with caching. I believe this started happening after we recently
changed the hostname from "webstage" to "www".

[Sun Feb 10 10:42:26.731666 2019] [cache_disk:error] [pid 997:tid
140189099861760] (2)No such file or directory: [client] AH00708: Cannot open data file

The .header file is there, and appears to contain info about robots.txt:

Mon, 04 Feb 2019 13:48:24 GMT
Content-Length: 882
ETag: "372-58111bf200a71"
Accept-Ranges: bytes
Cache-Control: max-age=300
Expires: Sun, 10 Feb 2019 14:36:31 GMT
Vary: User-Agent
Strict-Transport-Security: max-age=15768000
Content-Type: text/plain; charset=UTF-8

Accept: text/plain; charset=UTF-8
User-Agent: Jersey/2.6 (HttpUrlConnection 1.8.0_152)
If-None-Match: "372-58111bf200a71"
If-Modified-Since: Mon, 04 Feb 2019 13:48:24 GMT

I've removed the entirety of /var/cache/httpd/ and it is still
happening. I don't know how to reproduce it or what specifically caused it.

Below is the caching configuration from my virtual host:

CacheQuickHandler off
CacheLock on
CacheLockPath /tmp/mod_cache-lock
CacheLockMaxAge 5
CacheIgnoreHeaders Set-Cookie
CacheRoot "/var/cache/httpd"

<Location />
CacheEnable disk
CacheHeader on
CacheDefaultExpire 800
CacheMaxExpire 64000
CacheIgnoreNoLastMod On
ExpiresActive on
ExpiresDefault A300

Any ideas for how to debug this further would be greatly appreciated.