hi,
might be an authentication problem or string parsering problem
NAV Web Services are exposed by NAV 2009 or NAV 2013 ?
If NAV 2009 check:
> SPN & Trusted delegation for user running NAV Web Service (domain user) > ceck for ANONYMOUS login attempt in the SQL logs.
> use NTLM for autentication <add key="WebServicesUseNTLMAuthentication" value="true"></add>
> select using any protocol to connect and not kerberos only on service tier
> restart sql & all nav services
Two links
blog.artea.info/ms-nav-web-services-tofrom-php-receiving-and-sending-data
Freddy Blog
blogs.msdn.com/.../connecting-to-nav-web-services-from-php.aspx
try to change (suggested by Jega post): $response = trim(curl_exec($ch)) to remove spaces