diff --git a/dap4/src/main/java/dap4/core/dmr/parser/DOM4Parser.java b/dap4/src/main/java/dap4/core/dmr/parser/DOM4Parser.java
index 93a4a2c1df..8d437445ad 100644
--- a/dap4/src/main/java/dap4/core/dmr/parser/DOM4Parser.java
+++ b/dap4/src/main/java/dap4/core/dmr/parser/DOM4Parser.java
@@ -1,6 +1,6 @@
 /*
- * Copyright 2012, UCAR/Unidata.
- * See the LICENSE file for more information.
+ * Copyright (c) 2012-2026 University Corporation for Atmospheric Research/Unidata
+ * See LICENSE for license information.
  */
 
 package dap4.core.dmr.parser;
@@ -35,7 +35,8 @@ public class DOM4Parser implements Dap4Parser {
   // Constants
 
   static final float DAPVERSION = 4.0f;
-  static final float DMRVERSION = 1.0f;
+  static final float DMRVERSION_10 = 1.0f;
+  static final float DMRVERSION_20 = 2.0f;
 
   static final String DEFAULTATTRTYPE = "Int32";
 
@@ -461,9 +462,9 @@ protected void parsedataset(Node rootnode) throws ParseException {
       try {
         ndmrversion = Float.parseFloat(dmrversion);
       } catch (NumberFormatException nfe) {
-        ndmrversion = DMRVERSION;
+        ndmrversion = DMRVERSION_10;
       }
-    if (ndmrversion != DMRVERSION)
+    if (ndmrversion != DMRVERSION_10 && ndmrversion != DMRVERSION_20)
       throw new ParseException("Dataset dmrVersion mismatch: " + dmrversion);
     this.root = factory.newDataset(name);
     this.root.setDapVersion(Float.toString(ndapversion));
diff --git a/dap4/src/main/java/dap4/core/util/ChecksumMode.java b/dap4/src/main/java/dap4/core/util/ChecksumMode.java
index 9c341a0610..f42cbc11ac 100644
--- a/dap4/src/main/java/dap4/core/util/ChecksumMode.java
+++ b/dap4/src/main/java/dap4/core/util/ChecksumMode.java
@@ -1,6 +1,6 @@
 /*
- * Copyright 2012, UCAR/Unidata.
- * See the LICENSE file for more information.
+ * Copyright (c) 2012-2026 University Corporation for Atmospheric Research/Unidata
+ * See LICENSE for license information.
  */
 
 package dap4.core.util;
@@ -14,7 +14,7 @@ public enum ChecksumMode {
   FALSE, // => dap4.checksum=false
   TRUE; // => dap4.checksum=true
 
-  public static final ChecksumMode dfalt = TRUE; // Must be TRUE|FALSE
+  public static final ChecksumMode dfalt = FALSE; // Must be TRUE|FALSE
 
   static final String[] trues = new String[] {"true", "on", "yes", "1"};
   static final String[] falses = new String[] {"false", "off", "no", "0"};
diff --git a/dap4/src/test/java/dap4/test/TestHyrax.java b/dap4/src/test/java/dap4/test/TestHyrax.java
index 95b74159d3..ca795dcd5c 100644
--- a/dap4/src/test/java/dap4/test/TestHyrax.java
+++ b/dap4/src/test/java/dap4/test/TestHyrax.java
@@ -1,6 +1,6 @@
 /*
- * Copyright 2012, UCAR/Unidata.
- * See the LICENSE file for more information.
+ * Copyright (c) 2012-2026 University Corporation for Atmospheric Research/Unidata
+ * See LICENSE for license information.
  */
 
 package dap4.test;
@@ -22,12 +22,6 @@
 import java.util.List;
 import ucar.unidata.util.test.category.NeedsExternalResource;
 
-/**
- * This Test uses the JUNIT Version 4 parameterized test mechanism.
- * The set of arguments for each test is encapsulated in a class
- * called TestCase. This allows for code re-use and for extending
- * tests by adding fields to the TestCase object.
- */
 
 /**
  * This test set reads DAP4 datasets (both constrained and not)
@@ -48,7 +42,8 @@ public class TestHyrax extends DapTestCommon implements Dap4ManifestIF {
 
   // Define the input set location(s)
   protected static final String INPUTEXT = "";
-  protected static final String INPUTQUERY = "?dap4.checksum=true";
+  // request checksums true, false, and default
+  protected static final String[] INPUTQUERY = new String[] {"?dap4.checksum=true", "?dap4.checksum=false", ""};
   protected static final String INPUTFRAG = "#dap4&hyrax";
 
   protected static final String BASELINEDIR = "/baselinehyrax";
@@ -112,14 +107,24 @@ public static List<TestCaseCommon> defineTestCases() {
       String file = tuple[0];
       String prefix = tuple[1];
       String query = tuple[2]; // excluding leading '?'
-      // Unfortunately, The OPeNDAP test server does not appear to support https:
-      String url = server.getURL("http:") + "/" + prefix + "/" + file + INPUTEXT + INPUTQUERY;
-      if (query != null)
-        url += ("&" + DapConstants.CONSTRAINTTAG + "=" + query);
-      url += INPUTFRAG;
-      String baseline = resourceroot + BASELINEDIR + "/" + file + BASELINEEXT;
-      TestCase tc = new TestCase(file, url, baseline, query);
-      testcases.add(tc);
+      for (String IQ : INPUTQUERY) {
+        // Unfortunately, The OPeNDAP test server does not appear to support https:
+        String url = server.getURL("http:") + "/" + prefix + "/" + file + INPUTEXT + IQ;
+        System.out.println(url);
+        if (query != null) {
+          if (IQ.isEmpty()) {
+            url += ("?");
+          } else {
+            url += ("&");
+          }
+          url += (DapConstants.CONSTRAINTTAG + "=" + query);
+        }
+
+        url += INPUTFRAG;
+        String baseline = resourceroot + BASELINEDIR + "/" + file + BASELINEEXT;
+        TestCase tc = new TestCase(file, url, baseline, query);
+        testcases.add(tc);
+      }
     }
     return testcases;
   }
diff --git a/gradle/ncj.libs.versions.toml b/gradle/ncj.libs.versions.toml
index e69ee12d67..2fa9172ca4 100644
--- a/gradle/ncj.libs.versions.toml
+++ b/gradle/ncj.libs.versions.toml
@@ -39,7 +39,7 @@ junit4 = "4.13.1"
 junit5 = "5.14.0"
 junitparams = "1.0.5"
 mockito-core = "2.28.2"
-testcontainers = "1.19.7"
+testcontainers = "1.21.4"
 truth = "1.0"
 
 # runtime only