Let's Encrypt does not work on DA 1.55

Generating 4096 bit RSA key for let's encrypt account...
 openssl genrsa 4096 > "/usr/local/directadmin/data/users/******/letsencrypt.key"
 Generating RSA private key, 4096 bit long modulus
 ..............................................++
 .............++
 e is 65537 (0x10001)
 Account registration error. Response: HTTP/1.1 100 Continue 
 Expires: Tue, 05 Feb 2019 18:01:14 GMT 
 Cache-Control: max-age=0, no-cache, no-store 
 Pragma: no-cache 

 HTTP/1.1 400 Bad Request 
 Server: nginx 
 Content-Type: application/problem+json 
 Content-Length: 267 
 Replay-Nonce: ********** 
 Expires: Tue, 05 Feb 2019 18:01:14 GMT 
 Cache-Control: max-age=0, no-cache, no-store 
 Pragma: no-cache 
 Date: Tue, 05 Feb 2019 18:01:14 GMT 
 Connection: close 

 {
"type": "urn:acme:error:malformed",
"detail": "Provided agreement URL [https://letsencrypt.org/documents/LE-SA-v1.1.1-August-1-2016.pdf] does not match current agreement URL [https://letsencrypt.org/documents/LE-SA-v1.2-November-15-2017.pdf]",
"status": 400
 }.

cd /usr/local/directadmin/custombuild
./build update
./build letsencrypt

./build versions