diff --git a/src/tap/formatter/VOTableFormat.java b/src/tap/formatter/VOTableFormat.java
index d5e07c8bae09e3b9150a083517e6f4a4efcc3d11..ab2e76bf96386b9ddfd347d62a2b66fd9fbf7ae6 100644
--- a/src/tap/formatter/VOTableFormat.java
+++ b/src/tap/formatter/VOTableFormat.java
@@ -220,7 +220,7 @@ public class VOTableFormat implements OutputFormat {
 		out.newLine();
 
 		// Indicate that the query has been successfully processed:	[REQUIRED]
-		out.write("<INFO name=\"QUERY_STATUS\" value=\"ERROR\">" + VOSerializer.formatText(message) + "</INFO>");
+		out.write("<INFO name=\"QUERY_STATUS\" value=\"ERROR\">" + (message == null ? "" : VOSerializer.formatText(message)) + "</INFO>");
 		out.newLine();
 
 		// Append the PROVIDER information (if any):	[OPTIONAL]
diff --git a/src/tap/resource/Availability.java b/src/tap/resource/Availability.java
index fc10f97252ef4a2a29e3fb626e3dfd33b4dc8f42..003db0a66c78c1b059e34842d8255a3b2114e452 100644
--- a/src/tap/resource/Availability.java
+++ b/src/tap/resource/Availability.java
@@ -123,7 +123,8 @@ public class Availability implements TAPResource, VOSIResource {
 
 		// reason/description of the (non-)availability:
 		pw.print("\t<note>");
-		pw.print(VOSerializer.formatText(service.getAvailability()));
+		if (service.getAvailability() != null)
+			pw.print(VOSerializer.formatText(service.getAvailability()));
 		pw.println("</note>");
 
 		pw.println("</availability>");
diff --git a/src/tap/resource/TAP.java b/src/tap/resource/TAP.java
index 696d80adf939bf97c81b36f96571aa6720aebf32..cc45b25cd07f0a9267aae79f0019d9407707f28d 100644
--- a/src/tap/resource/TAP.java
+++ b/src/tap/resource/TAP.java
@@ -415,7 +415,7 @@ public class TAP implements VOSIResource {
 
 		// TAP access:
 		xml.append("\t<interface role=\"std\" xsi:type=\"vs:ParamHTTP\">\n");
-		xml.append("\t\t<accessURL use=\"base\">").append(VOSerializer.formatText(getAccessURL())).append("</accessURL>\n");
+		xml.append("\t\t<accessURL use=\"base\">").append((getAccessURL() == null) ? "" : VOSerializer.formatText(getAccessURL())).append("</accessURL>\n");
 		xml.append("\t</interface>\n");
 
 		// Language description:
@@ -678,7 +678,7 @@ public class TAP implements VOSIResource {
 			// Write the error in the response and return the appropriate HTTP status code:
 			errorWriter.writeError(t, response, request, reqID, owner, resourceName);
 			// Log the error:
-			getLogger().logHttp(LogLevel.ERROR, response, reqID, owner, "HTTP " + response.getStatus() + " - Can not complete the execution of the TAP resource \"" + resourceName + "\", because: " + t.getMessage(), t);
+			getLogger().logHttp(LogLevel.ERROR, response, reqID, owner, "HTTP " + response.getStatus() + " - Can not complete the execution of the TAP resource \"" + resourceName + "\"!", t);
 		}finally{
 			// Notify the queue of the asynchronous jobs that a new connection is available:
 			if (resourceName.equalsIgnoreCase(Sync.RESOURCE_NAME) && service.getFactory().countFreeConnections() >= 1)