How to Fix Runtime Error R6017 – Step by Step Guide Windows 11

Runtime errors can be a frustrating experience for software developers and users alike. One such error, “Runtime error R6017: Unexpected multithread lock”, is known to cause inconvenience and disrupt the smooth functioning of applications. In this article, we will explore the causes behind this error and provide step-by-step solutions to fix it.

Runtime Error R6017 is associated with C++ programming and typically occurs when there is fault in application code. The error message often reads: “unexpected multithread lock error”. This error can occur in various Windows operating systems, including Windows 7, 8, 10, and 11.

How to Fix How to Fix Runtime Error R6017 on Windows 11/10

There are several possible fixes are explained below that can resolve “Runtime error R6017: Unexpected multithread lock” from your computer. Apply the following methods step by step and check whether it fixes problem.

Fix using the Advanced System Repair tool.

Most commonly, the runtime error appears when dependency dll files are missing or corrupted. If your computer is unoptimized and has bugs, you may encounter various problems when running applications. It is recommended to use a reliable PC optimizer tool to repair any damages to your computer.

Windows is made with huge number of dll files, exe files, sys files, various types of services, databases, etc so, it is not possible to keep monitoring all the files always. A brilliant PC Optimizer tool repairs damages, fix errors, update windows and drivers, and eliminate various types of errors silently.

Outbyte PC Repair Tool does all the above task easily and provides you an errorfree and smooth Windows environment to work so that you can focus on your business only.

3 Steps to Fix this Error
Step 1. Download Outbyte PC Repair Tool [File Size: 16.4 MB]
Step 2. SCAN your Windows PC
Step 3. Click Fix button to Repair Error

Method 1: Repair or Reset the faulty application.

Repair/Reset the faulty application through the control panel should be the first step to fix any Runtime Error. You can repair an application as follows:

Windows 11 and Windows 10
Step 1: Go to Start → Settings → Apps → Installed Apps.


Step 2: Find the apps that is creating runtime error and click on the three dots (…) and select Modify or Advanced options.


Step 3: Scroll down to find Repair button and click on it to repair the faulty apps.


Step 4: If repairing the application didn’t work, try resetting it by clicking on the Reset button.


Windows 8, Windows 7 and Older Version
Step 1: Click on the Start button and Search for the Control Panel and Open it.


Step 2: Go to Programs → Uninstall a program.

uninstall program option in control panel

Step 3: Find the faulty apps → Right click on it → Select Change.


Step 4: Follow the instructions and select Repair option when you find it.


After repairing or resetting the application, Reboot your computer and run the application. If the problem didn’t solve, try next method.

Method 2: Install latest Microsoft Visual C++ Runtime Library.

If you are encountering runtime error R6017 or C Runtime Library error when installing an app or opening apps, it means you need to download the latest version of the MSVCR file and repair all the previous installed MSVCR files.

Step 1: To download this file, just google “Download Microsoft Visual C++ Redistributable” or open the following link. This library is free to download, install and use.

Step 2: Download the MSVCR Library file according to your System Architecture. If you don’t know what your System Architecture is, just click on Start Menu and search for “System Information”.


Step 3: Open System Information and here, you can see your CPU architecture.


Step 4: Download MSVCR Library and double click on it to install it.


Method 3: Repair previously installed Microsoft Visual C++ Runtime Library.

Most of the necessary Microsoft Visual C++ Redistributable Package is preinstalled with Windows Operating System and works like a charm with most of the apps. Unfortunately, sometimes it starts raising the problem with newly installed apps. This is because the newly installed apps could not bound themselves with the MSVCR file. In this situation, you need to repair the MSVCR installation to work correctly. Just follow the given steps to repair the pre-installed MS Visual C++ Redistributable Package.

Step 1: Open Settings. Go to Apps > Apps & Features.

apps & feature in windows 10/11

Step 2: Here, find all the installations with the name of “Microsoft Visual C++”, click on them and if Modify button is enabled, click on the Modify button.


Step 3: User Account Control dialog box will appear and will ask for your administrative permission. Click on the Yes button.
Step 4: The setup will start processing and you will see the following dialog box on the screen.


Step 5: After completing the repairing process, you will see the Setup Successful message on the screen.


Step 6: Do the same operation for all the MSVCR Installation which has enabled Modify button.
Step 7: Make a simple reboot and you have successfully repaired all your MSVCR Installation.

Method 4: Install latest .Net Framework.

If your PC doesn’t have installed the latest version of .Net Framework, then you are likely to get runtime error R6017. Go to the Microsoft official website, download the latest version of .NET Framework, and install it.

To install the latest version of the .NET Framework, you can follow these steps:

Step 1: Visit the official Microsoft .NET website:
Step 2: On the website, you’ll see the latest version of the .NET Framework available for download. Click on the download button for the version you want to install.

Method 5: Update entire Windows OS, Drivers, and Installed application.

It is important to keep your computer up to date by Installing the updates for Windows OS, Drivers, and all the installed Apps.

[Update Windows]
Step 1: Go to Settings ➜ Windows Update. Click on the Check for updates button and if shows any pending updates, download, and install them.

windows update settings in windows 11 & 10

[Update Drivers]
Step 2: Go to the Device Manager. Find the outdated drivers, right-click on them, and select Update.


[Update Apps]
Step 3: Open Microsoft Store. Go to the Library and click on the Get updates button.

update ms store apps

Method 6: Check updated version of apps.

There might be compatibility issue between apps and operating system. It is always a good idea to check for updated version of apps and installs it.


To fix the “Runtime error R6017: Unexpected multithread lock”: repair/reset the faulty apps, repair installed VC++ library, install the latest Visual C++ runtime library, update Windows and drivers, and apply additional solutions outlined in this article.