I downloaded a shaderpack from this site: https://minecraftshader.com/bsl-shaders/.

I saw that software is needed to run inside of Minecraft and OptiFine. I downloaded that too but I can't open it.

It seems that it needs another type of software to open the optifine.jar file.

I already tried installing WinRAR to see if it fixed the problem, but I didn't have any success.

  • 2
    Not trying to be rude but did you even read optifine's official documentation?
    – Skye-AT
    Jun 1 at 15:09
  • @Skye-AT people tend to ask questions when they can't figure out how to do things Jun 1 at 23:37
  • 1
    @Samstercraft I am aware of that. But I asked because there is step-to-step manual of how to install the optifine on their official post at minecraftforum(and it has three way to do so - simple/easy/complex installation option!). I asked because questioner doesn't seem to be read that.
    – Skye-AT
    Jun 2 at 0:36
  • You aren't being specific. Which type of Windows OS do you have (i.e. Windows 10 or 11)?
    – TimMcYeah
    Jun 2 at 12:51
  • @TimMcCool does OP even have windows?
    – Esther
    Jun 6 at 20:39

2 Answers 2


You probably don't have Java installed (which is needed to install almost any version of OptiFine). You can download it here.

You might also need to install Jarfix as well if you don't have that already. Just google "the breakdown optifine jarfix", if that also helps (like Java, you only need to install it again every few years to keep it updated).

  • Another thing: you mentioned that you downloaded software before. What specifically did you download?
    – TimMcYeah
    Jun 1 at 15:42
  • Also, since you're new, one thing to keep in mind when using Arqade (or anywhere on the Stack Exchange network) is to make sure that you add enough details when both asking a question and answering other peoples questions. If you don't add enough details, you might not get the answer that you need, because no one can read anybody's mind. Lastly, make sure that you mark an answer as which one helped you the best, even if there is only one.
    – TimMcYeah
    Jun 1 at 16:49
  • 1
    i wouldn't say they don't have it installed how did they run mc in the first place? but maybe wrong version, java versions can be confusing, or the jarfix Jun 1 at 23:38
  • 1
    @Samstercraft In case you didn't know that, Minecraft does not requires Java to be installed on the PC since 2017 (source). It is quite possible that questioner haven't installed Java.
    – Skye-AT
    Jun 2 at 8:55
  • @Skye-AT oh thats intresting ty Jun 3 at 5:24

You will need to install the Java Platform SE Binary. It seems like you are on Windows so after installing Java, right-click on the .JAR file and click Open With. Find the Java app you just installed and open it up. You will be prompted with an interface and you can install it.

IMPORTANT: Be careful with .JAR files because they can be dangerous and have security issues.

  • to be clear: .jar files are like .exe files, they contain code that will run on your computer, and just like you (hopefully) wouldn't run a random .exe you don't trust, you shouldn't run a random .jar you don't trust. They don't have more security issues than any other arbitrary code.
    – Esther
    Jun 6 at 20:42
  • The main reason I pointed it out is because Windows Defender can point out bad .exe's. If you use another antivirus it probably would detect bad .jar files
    – sleepstorm
    Jun 6 at 21:43

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