Hmm, its very random actually, first one didn't even start the game, this one was when i exited the game, third one was in the menus
Spoiler
104301 [Thread-6] DEBUG com.fs.graphics.TextureLoader - Loaded 255,77 MB of texture data so far
104302 [Thread-6] INFO com.fs.graphics.TextureLoader - Cleaned buffer for texture khs_graphics/backgrounds/background4.jpg (using cast)
173107 [Thread-6] INFO com.fs.starfarer.combat.CombatEngine - FP1: 3, FP2: 218, maxFP1: 80, maxFP2: 120
367684 [Thread-6] INFO com.fs.starfarer.campaign.save.CampaignGameManager - Reading save data from [..\saves\save_Anna_9181827609080721801\descriptor.xml]
367691 [Thread-6] INFO com.fs.starfarer.campaign.save.CampaignGameManager - Reading save data from [..\saves\save_DukeMadThane_7628977909357457719\descriptor.xml]
367693 [Thread-6] INFO com.fs.starfarer.campaign.save.CampaignGameManager - Reading save data from [..\saves\save_Maji_612983801662981655\descriptor.xml]
367693 [Thread-6] ERROR com.fs.starfarer.campaign.save.CampaignGameManager - : ParseError at [row,col]:[1,1]
Message: Content is not allowed in prolog.
com.thoughtworks.xstream.io.StreamException: : ParseError at [row,col]:[1,1]
Message: Content is not allowed in prolog.
at com.thoughtworks.xstream.io.xml.StaxReader.pullNextEvent(StaxReader.java:73)
at com.thoughtworks.xstream.io.xml.AbstractPullReader.readRealEvent(AbstractPullReader.java:148)
at com.thoughtworks.xstream.io.xml.AbstractPullReader.readEvent(AbstractPullReader.java:141)
at com.thoughtworks.xstream.io.xml.AbstractPullReader.move(AbstractPullReader.java:118)
at com.thoughtworks.xstream.io.xml.AbstractPullReader.moveDown(AbstractPullReader.java:103)
at com.thoughtworks.xstream.io.xml.StaxReader.<init>(StaxReader.java:45)
at com.thoughtworks.xstream.io.xml.StaxDriver.createStaxReader(StaxDriver.java:137)
at com.thoughtworks.xstream.io.xml.StaxDriver.createReader(StaxDriver.java:88)
at com.fs.starfarer.campaign.save.CampaignGameManager$3.createReader(Unknown Source)
at com.thoughtworks.xstream.XStream.fromXML(XStream.java:921)
at com.fs.starfarer.campaign.save.CampaignGameManager.?0000(Unknown Source)
at com.fs.starfarer.campaign.save.LoadGameDialog.<init>(Unknown Source)
at com.fs.starfarer.title.B.if.do$super(Unknown Source)
at com.fs.starfarer.title.B.super(Unknown Source)
at com.fs.starfarer.title.D.actionPerformed(Unknown Source)
at com.fs.starfarer.ui.O00o.super(Unknown Source)
at com.fs.starfarer.ui.F.processInput(Unknown Source)
at com.fs.starfarer.ui.newsuper.o00000(Unknown Source)
at com.fs.starfarer.new.?00(Unknown Source)
at com.fs.oOOO.super.new(Unknown Source)
at com.fs.starfarer.combat.D.o00000(Unknown Source)
at com.fs.starfarer.StarfarerLauncher$2.run(Unknown Source)
at java.lang.Thread.run(Thread.java:619)
Caused by: javax.xml.stream.XMLStreamException: ParseError at [row,col]:[1,1]
Message: Content is not allowed in prolog.
at com.sun.org.apache.xerces.internal.impl.XMLStreamReaderImpl.next(XMLStreamReaderImpl.java:593)
at com.thoughtworks.xstream.io.xml.StaxReader.pullNextEvent(StaxReader.java:58)
... 22 more
367693 [Thread-6] INFO com.fs.starfarer.campaign.save.CampaignGameManager - Reading save data from [..\saves\save_Nya_2843323585093413679\descriptor.xml]
367696 [Thread-6] INFO com.fs.starfarer.campaign.save.CampaignGameManager - Reading save data from [..\saves\save_wad_2581562814260949673\descriptor.xml]
369098 [Thread-6] INFO com.fs.starfarer.campaign.save.CampaignGameManager - Loading C:\Program Files (x86)\Fractal Softworks\Starsector\starsector-core\..\saves\save_wad_2581562814260949673...
371005 [Thread-6] INFO com.fs.starfarer.campaign.save.CampaignGameManager - Finished loading
371728 [Thread-6] DEBUG com.fs.graphics.TextureLoader - Loading image graphics/backgrounds/background4.jpg into existing tex id 315
372102 [Thread-6] DEBUG com.fs.graphics.TextureLoader - Loaded 267,77 MB of texture data so far
372103 [Thread-6] INFO com.fs.graphics.TextureLoader - Cleaned buffer for texture graphics/backgrounds/background4.jpg (using cast)
510759 [Thread-6] ERROR com.fs.starfarer.combat.D - java.lang.NullPointerException
java.lang.NullPointerException
at com.fs.starfarer.combat.ai.FighterAI.advance(Unknown Source)
at com.fs.starfarer.combat.CombatEngine.advance(Unknown Source)
at com.fs.starfarer.title.B.super(Unknown Source)
at com.fs.starfarer.new.?00(Unknown Source)
at com.fs.oOOO.super.new(Unknown Source)
at com.fs.starfarer.combat.D.o00000(Unknown Source)
at com.fs.starfarer.StarfarerLauncher$2.run(Unknown Source)
at java.lang.Thread.run(Thread.java:619)
Rolling my own mod and Kadur TheoCrazy.