How To Fix “Unable To Start Minecraft Runtime Environment” On CurseForge

CurseForge is a popular platform for gamers and modders alike, offering a vast library of mods and add-ons for various games.

However, some users have encountered an issue where CurseForge is unable to start the Minecraft runtime environment, preventing them from launching the game.

The complete error message reads: “Unable to start the Minecraft Runtime Environment. This is most likely caused by a corruption. Please try to reinstall Minecraft.”

In this article, we will explore the possible causes behind this problem and provide effective solutions to fix it.

Why Does CurseForge Unable To Start Minecraft Runtime Environment?

Many users have encountered the problem of not being able to start the Minecraft runtime environment when using CurseForge.

There are several reasons behind this issue.


One common cause is when the Minecraft Launcher and Java are installed on different drives, causing compatibility problems.

Another factor is if the CurseForge installation file is not located in the C drive, which can disrupt the smooth launching of Minecraft through CurseForge.

Additionally, firewall and antivirus software, important for system security, can sometimes interfere with CurseForge and Minecraft by blocking necessary connections or processes, leading to the runtime environment error.

How To Fix CurseForge Unable To Start Minecraft Runtime Environment?

curseforge unable to start minecraft runtime environment

Here are some fixes for the “Unable to start Minecraft runtime environment” issue:

1. Unistalll And Reinsall Minecraft

If you are facing this issue specifically with Minecraft, try uninstalling it from your PC, and then reinstall it from the official website.

Minecraft 1

To uninstall and reinstall, follow these steps

  • Press the Windows key + “I” to open the Settings menu.
  • Go to “Apps” or “Apps & features” in the Settings menu.
  • In the search bar, type “Minecraft” to locate the Minecraft application.
  • Once you find Minecraft in the list, click on it to select it.
  • Click on the three dots (or “More options”) button, usually located next to the app’s name.
  • From the dropdown menu, choose “Uninstall” to remove Minecraft from your PC.
  • Download the Minecraft installation file from the official website.
  • Once the download is complete, locate the file and run it to install Minecraft on your PC.

2. Check The Installation Location Of Minecraft Launcher And Java

Sometimes, the Minecraft runtime environment error occurs when the installation locations of Minecraft Launcher and Java are not aligned.

If you have installed Minecraft on a different drive or location than Java, it can lead to issues.

  • Start by uninstalling Minecraft from your system
  • Go to the Control Panel or Settings in your operating system, locate the Minecraft application, and choose to uninstall it.
  • After uninstalling Minecraft, reinstall it on the same drive where you have Java installed. This ensures that both Minecraft and Java are in the same location and can communicate properly.
  • This ensures that both Minecraft and Java are in the same location and can communicate properly.

3. Move CurseForge To C Drive

Try moving the CurseForge folder to your computer’s C Drive.

Some people have found success with this method because it helps with file path or permission issues that may be causing conflicts.

Here are the steps to do so:

  • Close the CurseForge application.
  • Locate the Curse folder’s current location.
  • Cut or copy the Curse folder.
  • Paste the folder into a desired location on the C Drive (e.g., C:\Curse).
  • Launch CurseForge and check if the error is resolved.

4. Repair CurseForge Installation

To fix the “Unable to start Minecraft runtime environment” error, you can try repairing the CurseForge installation.

By doing this, you can potentially resolve the error and get Minecraft running smoothly again.

To Repair Follow these steps:

  • Open the CurseForge application and navigate to the Minecraft tab on the left side.
  • Next to the “Create Custom Profile” option, click on the button located next to it.
  • From the dropdown menu, select the “Repair Installation” option.
  • This repair process is different from repairing a profile and is specific to the CurseForge instance. Rest assured that your modpacks and worlds will remain intact.

5. Disable Firewall And Antivirus

Sometimes, the firewall and antivirus software on your computer can cause problems with CurseForge and Minecraft, resulting in the “Unable to start Minecraft runtime environment” error.

One way to potentially fix this issue is by temporarily turning off.

To temporarily disable your antivirus software’s firewall, locate the antivirus program on your computer, open its settings, and disable the firewall feature.

To temporarily disable your firewall, follow these steps:

  • Open the Control Panel.
  • Search for “Windows Defender Firewall” or “Firewall.”
  • Select the appropriate network profile.
  • Choose the option to turn off the firewall for the selected profile.
  • Save the changes and exit the settings.

6. Run As Administrator

If CurseForge is unable to start the Minecraft runtime environment, try running the CurseForge launcher as an administrator.

To run CurseForge as an administrator, right-click on the application icon and select “Run as administrator.”

7. Change Launch Method And Java Version In Curse Config

In our research, we found that some users were able to resolve the issue by changing the launch method and Java version in the Curse Config.

Please check if this resolves the issue for you.

To change launch method and Java version in curse config, follow these steps:

  • Open the CurseForge application and click on the “Curse Config” button located in the bottom left corner.
  • In the left sidebar, search for “Minecraft config” (represented by a creeper face icon) and click on it.
  • Scroll down until you find the “Launch Method” option.
  • Change the launch method from “Native Launcher” to “Jar Launcher”.
  • Next, select the correct version of Java in the “Java Version” setting.

8. Move The Runtime Folder To Another Location

If the error occurs due to modpacks not working in the Curse Launcher folder, you can try resolving it by copying the Runtime folder from the Minecraft installation directory.

Follow these steps to move the Runtime folder to another location:

  • Navigate to the Minecraft installation directory, typically found in “Program Files” or “Program Files (x86)” on your system drive.
  • Locate the Runtime folder within the Minecraft installation directory.
  • Go to the Curse Launcher folder, where the modpacks are located.
  • Paste the copied Runtime folder into the Curse Launcher folder, replacing any existing Runtime folder.

9. Contact CurseForge Support

CurseForge Support

If none of the above steps resolves the error, it may be beneficial to reach out to CurseForge support for further assistance.