Are you sure this is a WebDAV server? Are you able to connect with any other WebDAV client?

I am receiving this error using the beta version to connect to a WebDav server. Here is the log:

. 2015-01-16 07:47:35.055 --------------------------------------------------------------------------
. 2015-01-16 07:47:35.055 WinSCP Version 5.6.5 RC (Build 4982) (OS 6.1.7601 Service Pack 1 - Windows 7 Professional)
. 2015-01-16 07:47:35.056 Configuration: C:\WINSCP\beta\WinSCP.ini
. 2015-01-16 07:47:35.056 Local account: LOCALDOMAIN\localuser
. 2015-01-16 07:47:35.056 Working directory: C:\WINSCP\beta
. 2015-01-16 07:47:35.056 Process ID: 1260
. 2015-01-16 07:47:35.056 Command-line: "C:\WINSCP\beta\WinSCP.exe"
. 2015-01-16 07:47:35.056 Time zone: Current: GMT-7, Standard: GMT-7 (Mountain Standard Time), DST: GMT-6 (Mountain Daylight Time), DST Start: 3/8/2015, DST End: 11/1/2015
. 2015-01-16 07:47:35.056 Login time: Friday, January 16, 2015 7:47:35 AM
. 2015-01-16 07:47:35.056 --------------------------------------------------------------------------
. 2015-01-16 07:47:35.056 Session name: WebDav Claim Shuttle (Site)
. 2015-01-16 07:47:35.056 Host name: www.claimshuttle.com (Port: 443)
. 2015-01-16 07:47:35.056 User name: FAKEUSERNAME (Password: Yes, Key file: No)
. 2015-01-16 07:47:35.056 Transfer Protocol: WebDAV
. 2015-01-16 07:47:35.056 Proxy: none
. 2015-01-16 07:47:35.056 Local directory: C:\Users\localuser\Documents, Remote directory: /, Update: Yes, Cache: Yes
. 2015-01-16 07:47:35.056 Cache directory changes: Yes, Permanent: Yes
. 2015-01-16 07:47:35.056 DST mode: 1
. 2015-01-16 07:47:35.056 Compression: No
. 2015-01-16 07:47:35.056 --------------------------------------------------------------------------
. 2015-01-16 07:47:35.116 HTTP session to https://www.claimshuttle.com:443 begins.
. 2015-01-16 07:47:35.566 ssl: SNI enabled by default.
. 2015-01-16 07:47:35.566 ah_create, for WWW-Authenticate
. 2015-01-16 07:47:35.566 Sending request headers:
. 2015-01-16 07:47:35.566 OPTIONS / HTTP/1.1
. 2015-01-16 07:47:35.566 User-Agent: WinSCP/5.6.5 neon/0.30.1
. 2015-01-16 07:47:35.566 Keep-Alive:
. 2015-01-16 07:47:35.566 Connection: TE, Keep-Alive
. 2015-01-16 07:47:35.566 TE: trailers
. 2015-01-16 07:47:35.566 Host: www.claimshuttle.com
. 2015-01-16 07:47:35.566
. 2015-01-16 07:47:35.566 Sending request-line and headers:
. 2015-01-16 07:47:35.566 Doing DNS lookup on www.claimshuttle.com...
. 2015-01-16 07:47:35.570 req: Connecting to 162.42.205.85:443
. 2015-01-16 07:47:35.570 Doing SSL negotiation.
. 2015-01-16 07:47:35.731 ssl: Verify callback @ 2 => 19
. 2015-01-16 07:47:35.732 ssl: Verify failures |= 8 => 8
. 2015-01-16 07:47:36.071 Chain depth: 3
. 2015-01-16 07:47:36.071 ssl: Match common name 'www.claimshuttle.com' against ''
. 2015-01-16 07:47:36.071 ssl: Match common name 'claimshuttle.com' against ''
. 2015-01-16 07:47:36.071 Identity match for '': bad
. 2015-01-16 07:47:36.071 ssl: Match common name 'Go Daddy Secure Certification Authority' against ''
. 2015-01-16 07:47:36.071 Identity match for '': bad
. 2015-01-16 07:47:36.071 ssl: Match common name 'www.claimshuttle.com' against 'www.claimshuttle.com'
. 2015-01-16 07:47:36.071 Identity match for 'www.claimshuttle.com': good
. 2015-01-16 07:47:36.071 Verifying certificate for "Domain Control Validated" with fingerprint 65:24:7a:be:36:5f:ab:98:b5:9e:68:f0:9a:bc:4d:32:05:56:47:a5 and 08 failures
. 2015-01-16 07:47:36.088 Certificate verified against Windows certificate store
. 2015-01-16 07:47:36.088 Using TLSv1, cipher TLSv1/SSLv3: ECDHE-RSA-AES128-SHA, 2048 bit RSA
. 2015-01-16 07:47:36.088 Request sent; retry is 0.
. 2015-01-16 07:47:36.145 [status-line] < HTTP/1.1 200 OK
. 2015-01-16 07:47:36.145 Header Name: [allow], Value: [GET,HEAD,POST,OPTIONS]
. 2015-01-16 07:47:36.145 Header Name: [content-length], Value: [0]
. 2015-01-16 07:47:36.145 Header Name: [server], Value: [Jetty(7.5.3.v20111011)]
. 2015-01-16 07:47:36.145 End of headers.
. 2015-01-16 07:47:36.168 ah_post_send (#0), code is 200 (want 401), WWW-Authenticate is (none)
. 2015-01-16 07:47:36.168 Request ends, status 200 class 2xx, error line:
. 2015-01-16 07:47:36.168 200 OK
. 2015-01-16 07:47:36.168 Request ends.
. 2015-01-16 07:47:36.168 --------------------------------------------------------------------------
. 2015-01-16 07:47:36.168 Using WebDAV protocol.
. 2015-01-16 07:47:36.169 Doing startup conversation with host.
. 2015-01-16 07:47:36.218 Changing directory to "/".
. 2015-01-16 07:47:36.218 Trying to open directory "/".
. 2015-01-16 07:47:36.218 ah_create, for WWW-Authenticate
> 2015-01-16 07:47:36.218 <?xml version="1.0" encoding="utf-8"?>
> 2015-01-16 07:47:36.218 <propfind xmlns="DAV:"><allprop/></propfind>
. 2015-01-16 07:47:36.218 Sending request headers:
. 2015-01-16 07:47:36.218 PROPFIND / HTTP/1.1
. 2015-01-16 07:47:36.218 User-Agent: WinSCP/5.6.5 neon/0.30.1
. 2015-01-16 07:47:36.218 Connection: TE
. 2015-01-16 07:47:36.218 TE: trailers
. 2015-01-16 07:47:36.219 Host: www.claimshuttle.com
. 2015-01-16 07:47:36.219 Depth: 0
. 2015-01-16 07:47:36.219 Content-Length: 84
. 2015-01-16 07:47:36.219 Content-Type: application/xml
. 2015-01-16 07:47:36.219
. 2015-01-16 07:47:36.219 Sending request-line and headers:
. 2015-01-16 07:47:36.219 Sending request body:
. 2015-01-16 07:47:36.219 Request sent; retry is 1.
. 2015-01-16 07:47:36.369 [status-line] < HTTP/1.1 501 Method PROPFIND is not defined in RFC 2068 and is not supported by the Servlet API
. 2015-01-16 07:47:36.369 Header Name: [content-length], Value: [0]
. 2015-01-16 07:47:36.369 Header Name: [server], Value: [Jetty(7.5.3.v20111011)]
. 2015-01-16 07:47:36.369 End of headers.
. 2015-01-16 07:47:36.369 ah_post_send (#0), code is 501 (want 401), WWW-Authenticate is (none)
. 2015-01-16 07:47:36.369 Request ends, status 501 class 5xx, error line:
. 2015-01-16 07:47:36.369 501 Method PROPFIND is not defined in RFC 2068 and is not supported by the Servlet API
. 2015-01-16 07:47:36.369 Request ends.
* 2015-01-16 07:47:36.369 (ECommand) Error changing directory to '/'.
* 2015-01-16 07:47:36.369 501 Method PROPFIND is not defined in RFC 2068 and is not supported by the Servlet API
. 2015-01-16 07:47:38.645 Getting current directory name.
. 2015-01-16 07:47:38.796 ah_create, for WWW-Authenticate
> 2015-01-16 07:47:38.796 <?xml version="1.0" encoding="utf-8"?>
> 2015-01-16 07:47:38.796 <propfind xmlns="DAV:"><allprop/></propfind>
. 2015-01-16 07:47:38.796 Sending request headers:
. 2015-01-16 07:47:38.796 PROPFIND / HTTP/1.1
. 2015-01-16 07:47:38.796 User-Agent: WinSCP/5.6.5 neon/0.30.1
. 2015-01-16 07:47:38.796 Connection: TE
. 2015-01-16 07:47:38.796 TE: trailers
. 2015-01-16 07:47:38.796 Host: www.claimshuttle.com
. 2015-01-16 07:47:38.796 Depth: 1
. 2015-01-16 07:47:38.796 Content-Length: 84
. 2015-01-16 07:47:38.796 Content-Type: application/xml
. 2015-01-16 07:47:38.796
. 2015-01-16 07:47:38.796 Sending request-line and headers:
. 2015-01-16 07:47:38.796 Sending request body:
. 2015-01-16 07:47:38.796 Request sent; retry is 1.
. 2015-01-16 07:47:38.946 [status-line] < HTTP/1.1 501 Method PROPFIND is not defined in RFC 2068 and is not supported by the Servlet API
. 2015-01-16 07:47:38.946 Header Name: [content-length], Value: [0]
. 2015-01-16 07:47:38.946 Header Name: [server], Value: [Jetty(7.5.3.v20111011)]
. 2015-01-16 07:47:38.946 End of headers.
. 2015-01-16 07:47:38.946 ah_post_send (#0), code is 501 (want 401), WWW-Authenticate is (none)
. 2015-01-16 07:47:38.946 Request ends, status 501 class 5xx, error line:
. 2015-01-16 07:47:38.946 501 Method PROPFIND is not defined in RFC 2068 and is not supported by the Servlet API
. 2015-01-16 07:47:38.946 Request ends.
* 2015-01-16 07:47:39.046 (ECommand) Error listing directory '/'.
* 2015-01-16 07:47:39.046 501 Method PROPFIND is not defined in RFC 2068 and is not supported by the Servlet API
. 2015-01-16 07:47:39.944 Startup conversation with host finished.
. 2015-01-16 07:47:44.127 sess: Destroying session.
. 2015-01-16 07:47:44.127 sess: Closing connection.
. 2015-01-16 07:47:44.127 sess: Connection closed.