JNBridgePro v12 Crash Fix: x86 Shared Memory and a Hidden VC++ Runtime Dependency

Some production bugs are not really “your code” bugs — they’re dependency-chain bugs hiding underneath the runtime. This one is a good example: an x86 shared-memory setup crashes with an access violation, but the actual cause is a missing native DLL required by the JVM.

If you're running JNBridgePro v12 with 32-bit shared memory, here's how to recognize the failure, confirm the root cause, and fix it without chasing phantom memory corruption.

The Symptom: x86 Shared Memory Crashes Early

Users running JNBridgePro v12 may encounter a crash when using the x86 Shared-Memory transport. The issue does not appear in prior versions or in other configurations, and it only shows up under a specific combination of runtime choices.

When running unit tests or demo applications using x86 Shared-Memory transport, you may see:

System.AccessViolationException: Attempted to read or write protected memory.

It often happens during an early Java proxy call, such as:

new java.util.HashMap()

The crash occurs only when all of these are true:

• The process is compiled for x86
• Shared-Memory transport is used
• A standard Oracle JRE is installed, for example jre1.8.0_202
• JNBridgePro v12 is being used

For background on how shared memory works in a .NET-to-Java project, see the related walkthrough: Anatomy of a Shared Memory Bridge.

Root Cause: jvm.dll Depends on the VC++ 2010 Runtime

The issue is caused by a runtime dependency inside the JVM itself, not by JNBridgePro.

Many Oracle 32-bit JRE distributions include a jvm.dll built with Visual Studio 2010. That means the DLL dynamically depends on the Microsoft Visual C++ 2010 Runtime, specifically:

msvcr100.dll

If that runtime is missing, Windows cannot fully load the JVM. Unfortunately, the failure is not always surfaced cleanly. Instead of a direct “missing DLL” error, the process can drift into memory corruption and eventually fail with System.AccessViolationException.

This shows up with Shared-Memory transport because the JVM is loaded directly into the .NET process. When the JVM is in-process, all of the JVM's native dependencies must be available to that same process at runtime.

Why Earlier Versions May Not Have Failed

Earlier versions of JNBridgePro bundled the Microsoft Visual C++ 2010 Redistributable, which meant this dependency was usually present by default.

JNBridgePro v12 no longer includes that redistributable. On clean systems where the VC++ 2010 runtime is not already installed, the hidden dependency can now surface.

That explains the confusing pattern:

How to Confirm the Cause

The fastest way to confirm the root cause is to watch for msvcr100.dll during startup.

Option 1: Use Procmon

1. Open Process Monitor
2. Add a filter:

Path contains msvcr100.dll → Include

3. Run your x86 Shared-Memory test
4. Look for attempts to access msvcr100.dll

If you see those events, the JVM is depending on the VC++ 2010 runtime.

Option 2: Use dumpbin

You can inspect the JVM DLL directly:

dumpbin /dependents path\to\jvm.dll

If msvcr100.dll appears in the dependency list, you've found the issue.

Option 3: Use Dependencies.exe

Open jvm.dll in Dependencies and inspect the native dependency tree visually. This is often the clearest option when debugging a clean Windows machine or a build agent.

Fix 1: Use a Different 32-bit JRE

One fix is to switch to a 32-bit JRE whose jvm.dll does not depend on the VC++ 2010 runtime.

For example, the 32-bit jvm.dll from Zulu OpenJDK 8 was tested successfully and did not require msvcr100.dll.

This is often the cleaner option if you control the runtime distribution and want fewer machine-level prerequisites.

Fix 2: Install the VC++ 2010 Redistributable

The other fix is to install the Microsoft Visual C++ 2010 Redistributable Package (x86).

That provides the missing msvcr100.dll dependency required by the JVM.

Use this option when:

• You need to stay on the current Oracle JRE
• You are repairing an existing environment
• You want the smallest change to a known-good deployment

Practical Takeaway

If JNBridgePro v12 crashes at startup in an x86 Shared-Memory configuration, do not start by assuming application-level memory corruption. First check whether the JVM can actually load all of its native dependencies.

The short checklist:

• Confirm the process is x86
• Confirm Shared-Memory transport is being used
• Check jvm.dll dependencies
• Look for msvcr100.dll
• Either switch JRE builds or install the VC++ 2010 Redistributable

Once identified, this issue is usually quick to fix. The hard part is recognizing that the access violation is a symptom of a missing native runtime dependency, not the root problem.

Originally published on the JNBridge blog: JNBridgePro v12 Crash Fix: x86 Shared Memory and Hidden VC++ Runtime Dependency.