Pihole web interface doesn't work!

[al001]

i have installed pihole and dnscrypt on ubuntu server 18.04 lts, i have 3 days the web interface doesn't work, i try pinhole -r to reconfigure but nothing change
when i do pihole -r show me this.

** [ DIAGNOSING ]: Dashboard and block page
[✗] Block page X-Header: X-Header does not match or could not be retrieved.
HTTP/1.1 200 OK
Date: Thu, 28 Mar 2019 13:44:57 GMT
Server: Apache/2.4.29 (Ubuntu)
Last-Modified: Wed, 20 Mar 2019 14:51:37 GMT
ETag: "2aa6-58487c23e5cec"
Accept-Ranges: bytes
Content-Length: 10918
Vary: Accept-Encoding
Content-Type: text/html

[✗] Web interface X-Header: X-Header does not match or could not be retrieved.
HTTP/1.1 200 OK
Date: Thu, 28 Mar 2019 13:44:57 GMT
Server: Apache/2.4.29 (Ubuntu)
Last-Modified: Mon, 18 Mar 2019 13:20:42 GMT
ETag: "2a3b-5845e416a3dc3"
Accept-Ranges: bytes
Content-Length: 10811


*** [ DIAGNOSING ]: Pi-hole processes
[✗] lighttpd daemon is failed
[✓] pihole-FTL daemon is active

[jfb]

@al001

Server: Apache/2.4.29 (Ubuntu)

This is because you are running Apache2 and this is interfering with lighttpd, which also runs on port 80.