Detected leaking worlds in memory.

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New Member
Jul 29, 2019
I'm getting the same problem :mad: i didn't backup my world because i'm "sooo" smart i had a diamond factory going and an applied engergistics sorting system D:<


New Member
Jul 29, 2019
Ok, lets try some things out here...
  1. Open the FTB Launcher.
  2. Under the options tab, go to advanced, and type this into the Java parameters:
  • MAKE SURE IT IS EXACTLY AS WRITTEN! You will get errors if there are any extra spaces/letters/special chars.... Please double check.
Less then 2GB of ram
-Xms256m -XX:PermSize=128M -XX:MaxPermSize=256m
More then 2GB or ram
-Xms512m -XX:PermSize=128M -XX:MaxPermSize=512m
  • So what this does is:
    1. -Xms: set initial Java heap size.
    2. -Xmx: set maximum Java heap size. (Not in code, this is set by the slider.)
    3. -XX: PermSize: Size of the Permanent Generation.
    4. -XX:MaxPermSize: Maximum Size of the Permanent Generation.
So... Try these, and re-post to pastebin if it don't work.

Why you ask?
So the idea I have come to is that with so many mods, Java is running out of memory.

  • "What? but i gave it two gigs of ram in the launcher"
Well, Java actually uses Two different memory settings. The slider in the launcher only touches one of them. This will change the other way that Java uses memory.

  • "Why is that happening now oh wise man?"
Basically, (Not pointing fingers), It is because most of the people who are creating these wonderful amazing mods we like to play with are sorta kinda new to java programing. (SOME of the people, KINDA SORTA new. :DI love you all ) These problems will go away as the people get better at programming. No, there is nothing right now that we can do to solve a lot of these issues. (You could always help out the mod programmers and the FTB launcher guys if you really want to by DONATING to them. This will allow them to have more incentive/free-time to become better at Java.)

{edit} Realized that the numbers were exactly the same.... oops
{edit} Changed Parameters.
{edit} Added the warning at the top.
{edit} Clarified some instructions
{edit} Removed space from Java Parameters, Thanks Phil_Aus
{edit} Need to add INSIDE of FTB, TYVM Furious1964
ok nvm i had to use the less then 2 gb one. is there any particular reason my launcher wont let me go above 1gb?
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