System.IO.FileNotFoundException: The Web application at ..not found - when getting document versions in a doc lib

Question

i have created a    asmx file using vs 2012 4.5 framework, and published to my d:\  drive  and mapped to a  iis  web site
but when i trued to consume this from a another web appln, it throws me the below error:
 System.IO.FileNotFoundException: The Web application at http://srvr:4000/sites/mysitecollec could not be found. Verify that you have typed the URL correctly. If the URL should be serving existing content, the system administrator may need to add a
new request URL mapping to the intended application.
   at Microsoft.SharePoint.SPSite.LookupSiteInfo(SPFarm farm, Boolean contextSite, Boolean swapSchemeForPathBasedSites, Uri& requestUri, Boolean& lookupRequiredContext, Guid& applicationId, Guid& contentDatabaseId, Guid& siteId,
Guid& siteSubscriptionId, SPUrlZone& zone, String& serverRelativeUrl, Boolean& hostHeaderIsSiteName, Boolean& appWebRequest, String& appHostHeaderRedirectDomain, String& appSiteDomainPrefix, String& subscriptionName, String&
appSiteDomainId, Uri& primaryUri)
   at Microsoft.SharePoint.SPSite..ctor(SPFarm farm, Uri requestUri, Boolean contextSite, Boolean swapSchemeForPathBasedSites, SPUserToken userToken)
   at Microsoft.SharePoint.SPSite..ctor(SPFarm farm, Uri requestUri, Boolean contextSite, SPUserToken userToken)
   at Microsoft.SharePoint.SPSite..ctor(String requestUrl)
   at FetchlatestDocDet6Jan.FetchLatestDoc6Jan.<>c__DisplayClass1.<FetchLatestDocVer>b__0() in d:\PublishWSFetchLatestDoc6Jan.asmx.cs:line 41
   at Microsoft.SharePoint.SPSecurity.<>c__DisplayClass5.<RunWithElevatedPrivileges>b__3()
   at Microsoft.SharePoint.Utilities.SecurityContext.RunAsProcess(CodeToRunElevated secureCode)
   at Microsoft.SharePoint.SPSecurity.RunWithElevatedPrivileges(WaitCallback secureCode, Object param)
   at Microsoft.SharePoint.SPSecurity.RunWithElevatedPrivileges(CodeToRunElevated secureCode)
   at FetchlatestDocDet6Jan.FetchLatestDoc6Jan.FetchLatestDocVer(String fileName, String processID, String subProcessId) in d:\PublishedWS\FetchLatestDoc6Jan.asmx.cs:line 35
[WebMethod]
        public DataTable FetchLatestDocVer(string fileName,string processID,string subProcessId)
            DataTable dtFiles = new DataTable("File Details");
            dtFiles.Columns.Add("File Name");
            dtFiles.Columns.Add("File Version");
            dtFiles.Columns.Add("File Url");
            SPSecurity.RunWithElevatedPrivileges(delegate()
                // implementation details omitted       
            //using (SPSite mySite = new SPSite(siteUrl))
            using (SPSite mySite = new SPSite("http://srvr:4000/sites/mysitecoll"))
                using (SPWeb myWeb = mySite.OpenWeb())
                    SPList oList = myWeb.Lists["TEST DOC LIB "];
                    SPView oView = oList.Views["All Documents"];                  // SPQuery oQuery = new SPQuery(oView);
                    SPQuery oQuery = new SPQuery();
                    string query = "<Query><Where><And><Eq><FieldRef Name=Title/>" + "<Value Type=Text>" + fileName + "</Value></Eq>"
                                    +"<Eq><FieldRef Name=ProcessID /><Value Type=Text>"+processID+"</Value></Eq>"
                                    +"<Eq><FieldRef Name=SubProcessID /><Value Type=Text>"+subProcessId+"</Value></Eq>"
                                    +"</And></Where></Query>";
                    oQuery.Query = query;                    
                    oQuery.ViewAttributes = "Scope=\"Recursive\"";
                    SPListItemCollection collListItemsAvailable =
                     oList.GetItems(oQuery);
                    foreach (SPListItem oListItemAvailable in collListItemsAvailable)
                       // Console.WriteLine(oListItemAvailable["Name"].ToString());
                        SPFileVersionCollection versions = oListItemAvailable.File.Versions;
                        // If the file has versions, loop through all of the versions
                        if (versions != null)
                            if (versions.Count > 0)
                                foreach (SPFileVersion version in versions)
                                 //   Console.WriteLine("Version Info:: {0}, {1}", version.VersionLabel, version.Url);
                                    DataRow dr = dtFiles.NewRow();
                                    dr[0] = oListItemAvailable["Name"].ToString();
                                //Added data to the datatable
                            else
                              //  Console.WriteLine("Version Info:: {0}, {1}", oListItemAvailable.File.UIVersionLabel, oListItemAvailable.File.Url);
                                DataRow dr = dtFiles.NewRow();
                                dr[0] = oListItemAvailable["Name"].ToString();
                                dr[1] = oListItemAvailable.File.UIVersionLabel;
                                dr[2] = oListItemAvailable.File.Url;
                                dtFiles.Rows.Add(dr);
            return dtFiles;

Answer 1

"The Web application at http://server:port/ could not be found. Verify that you have typed the URL correctly. If the URL should be serving existing
content, the system administrator may need to add a new request URL mapping to the intended application"
Here are the most common reasons this error can occur:
The code is executed on a different machine - The SharePoint object model (except the Client API) requires to be run on the SharePoint server itself. It is not possible to run the application on a server which is not within the same
SharePoint farm the code is trying to access.
Insufficient Rights on the site collection - The code is executed in context of an account which does not have read permission on the site collection
Incorrect Url being used - Verify that the site works correct in a browser and double check that the server is correct registered in the AAM settings
Incorrect bitness - The SharePoint object model needs to be executed with the same bitness as the operating system. That means you cannot use the SharePoint object model in a 32-bit application if the Operating System and SharePoint
are installed as 64-bit version. Ensure to compile the project using the correct bitness (64-bit on a 64-bit machine vs. 32-bit on a 32-bit machine)
Incorrect .NET framework version -  Ensure that the project is configured to use .NET 3.5. .NET 4.0 cannot be used with the current versions of SharePoint
from Mr.Stefan's post, i have checked with my code : as per the first reason: (1)
i am running the code from my  SP 2013 machine only. but the only difference is that, i am using a  asp.net web appln and have added a SP references of 15 hive and trying to make a  lists.asmx file.
also checked the reasons
2,3 ,4 ,5 all are  fine from my end.
here just wanna know: abt the below approach : whether its Correct or NOT.
create a plain GetDocsWebService.asmx file from asp.net 3.5 framework and  write the code for retrieving items from doc.lib using SPSite, spweb, splists, xmldocument and retrieve a datatable . [[[ i have added a web reference of sp 2013 microsoft.sharepoint
dll from  isapi folder, in this GetDocsWebService.asmx project ]]
i deployed this web service on my SP server's  new iis site, c:\inetpub\wwwroot\GETDOCSPUBLISH  site
now, at present , am adding a  normal asp.net 4.5 web appln and add the  web reference of this custom web service and trying to consume.
at this point am getting mulitpl errors: like
1) platform not supported : am stuck with this error!!
2) sometimes, am getting document not valid...<html> <head> document not valid........</html>
for the above 2 errorrs, i still could not able to find a solution!!
is it because, lists.asmx is not supported in sp 2013? we need to depend on rest-api/ecma/csom ?? 
so my question is ,  what should be the correct ad most recommended approach  for reading doc lib/ splist  records/items from a  remote macihne.