Index: modules/core/src/test/java/org/apache/ignite/internal/processors/cache/transactions/TxOnCachesStopTest.java
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- modules/core/src/test/java/org/apache/ignite/internal/processors/cache/transactions/TxOnCachesStopTest.java	(revision 78faf08f08d98bde4457600f1e4ee0c39af2c66b)
+++ modules/core/src/test/java/org/apache/ignite/internal/processors/cache/transactions/TxOnCachesStopTest.java	(date 1597718184221)
@@ -23,6 +23,12 @@
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
+import javassist.CannotCompileException;
+import javassist.ClassPool;
+import javassist.CtClass;
+import javassist.CtMethod;
+import javassist.CtNewMethod;
+import javassist.NotFoundException;
 import javax.cache.CacheException;
 import org.apache.ignite.Ignite;
 import org.apache.ignite.IgniteCache;
@@ -61,7 +67,7 @@
 import org.junit.Test;
 
 import static org.apache.ignite.transactions.TransactionConcurrency.OPTIMISTIC;
-import static org.apache.ignite.transactions.TransactionIsolation.SERIALIZABLE;
+import static org.apache.ignite.transactions.TransactionIsolation.*;
 
 /**
  *
@@ -161,6 +167,101 @@
         runTxOnCacheStop(true);
     }
 
+    /**
+     * Case: stop cache in transaction load
+     * interfere with the work of parallel threads forcing them to cleanup context before using it
+     * @throws Exception If failed.
+     */
+    @Test
+    public void testTxOnCacheStopWithClassTransformation() throws Exception {
+        classTransformation();
+
+        runTxOnCacheStop(false);
+    }
+
+    /**
+     * Blocking to arrange processing in the desired sequence.
+     */
+    public static CountDownLatch latch;
+
+    /**
+     *  adding code to classes
+     *  hold
+     *  CacheObject.finishUnmarshal()
+     *  until completing
+     *  GridCacheContext.cleanup()
+     * @throws NotFoundException
+     * @throws CannotCompileException
+     */
+    private void classTransformation() throws NotFoundException, CannotCompileException {
+        ClassPool classPool = ClassPool.getDefault();
+        {
+            CtClass binaryObjectImpl = classPool.get("org.apache.ignite.internal.processors.cache.KeyCacheObjectImpl");
+
+            CtMethod finishUnmarshalOld = binaryObjectImpl.getDeclaredMethod("finishUnmarshal");
+
+            finishUnmarshalOld.setName("finishUnmarshalOld");
+
+            CtMethod finishUnmarshal = CtNewMethod.copy(finishUnmarshalOld, "finishUnmarshal", binaryObjectImpl, null);
+
+            finishUnmarshal.setBody("{\n" +
+                "    if(org.apache.ignite.internal.processors.cache.transactions.TxOnCachesStopTest.latch != null){\n" +
+                "        try {\n" +
+                "            org.apache.ignite.internal.processors.cache.transactions.TxOnCachesStopTest.latch.await(2500L, java.util.concurrent.TimeUnit.MILLISECONDS);\n" +
+                "        }\n" +
+                "        catch (java.lang.Exception  e){\n" +
+                "        }\n" +
+                "    }\n" +
+                "    return finishUnmarshalOld($$);\n" +
+                "}");
+
+            binaryObjectImpl.addMethod(finishUnmarshal);
+
+            binaryObjectImpl.toClass(getClass().getClassLoader(), null);
+        }
+
+        {
+            CtClass gridCacheContext = classPool.get("org.apache.ignite.internal.processors.cache.GridCacheContext");
+
+            CtMethod cleanupOld = gridCacheContext.getDeclaredMethod("cleanup");
+
+            cleanupOld.setName("cleanupOld");
+
+            CtMethod cleanup = CtNewMethod.copy(cleanupOld, "cleanup", gridCacheContext, null);
+
+            cleanup.setBody("{\n" +
+                "   cleanupOld();\n" +
+                "   if(org.apache.ignite.internal.processors.cache.transactions.TxOnCachesStopTest.latch != null) {\n" +
+                "       org.apache.ignite.internal.processors.cache.transactions.TxOnCachesStopTest.latch.countDown();\n" +
+                "   }\n" +
+                "}");
+
+            gridCacheContext.addMethod(cleanup);
+
+            gridCacheContext.toClass(getClass().getClassLoader(), null);
+        }
+
+        {
+            CtClass cacheObjectByteArrayImpl = classPool.get("org.apache.ignite.internal.processors.cache.CacheObjectByteArrayImpl");
+
+            CtMethod finishUnmarshalOld = cacheObjectByteArrayImpl.getDeclaredMethod("finishUnmarshal");
+
+            finishUnmarshalOld.setName("finishUnmarshalOld");
+
+            CtMethod finishUnmarshal = CtNewMethod.copy(finishUnmarshalOld, "finishUnmarshal", cacheObjectByteArrayImpl, null);
+
+            finishUnmarshal.setBody("{\n" +
+                "    if ($1 == null)\n" +
+                "        org.junit.Assert.fail(\"ctx is null, what will cause the error NullPointerException\");\n" +
+                "   finishUnmarshalOld($$);\n" +
+                "}");
+
+            cacheObjectByteArrayImpl.addMethod(finishUnmarshal);
+
+            cacheObjectByteArrayImpl.toClass(getClass().getClassLoader(), null);
+        }
+    }
+
     /**
      * @param block {@code True} To block GridNearTxPrepareRequest message.
      */
@@ -295,8 +396,12 @@
                     spi.stopBlock();
                 });
 
+                latch = new CountDownLatch(1);
+
                 cache.destroy();
 
+                latch = null;
+
                 f.get();
             }
             catch (Exception e) {