maintenance expiration vs build date checking code

server/AyaNova/util/License.cs

@@ -799,7 +799,7 @@ namespace AyaNova.Core
                     throw new ApplicationException("E1020 - Can't install a trial key into a non empty AyaNova database.  Erase the database first.");
                 }
 
-                //TODO: TECHCOUNT - new license causes exceeding count?  
+                //TECHCOUNT - new license causes exceeding count?  
                 long NewTechCount = ParsedNewKey.GetLicenseFeature(SERVICE_TECHS_FEATURE_NAME).Count;
                 if (await AyaNova.Biz.UserBiz.ActiveCountAsync() > NewTechCount)
                 {
@@ -925,6 +925,15 @@ EQIDAQAB
 
 
                 #endregion get values
+
+                //Check if attempting to use a build of AyaNova that is newer than maintenance subscription expiry 
+                if (MExBB(Util.FileUtil.GetLinkerTimestampUtc(System.Reflection.Assembly.GetExecutingAssembly()), key))
+                {
+                    Console.WriteLine("E1020 - Not licensed for this version of AyaNova. Fix: downgrade back to previous version in use or contact technical support for options.");                    
+                    
+                    //NOTE: VERSION-TOO-NEW  bit below is checked for in startup.cs DO NOT remove this without fixing the side effects
+                    throw new ApplicationException("E1020 VERSION-TOO-NEW - Not licensed for this version of AyaNova. Fix: downgrade back to previous version in use or contact technical support for options.");
+                }
                 //All is well return key
                 return key;
 
@@ -942,6 +951,12 @@ EQIDAQAB
 
 
 
+        #region Validate Build date against maintenance date in license
+        //MaintenanceExpirationBeforeBuild?
+        internal static bool MExBB(DateTime dtB, AyaNovaLicenseKey k) => k.MaintenanceExpiration < dtB;
+        #endregion
+
+
 
     }//eoc