error where found some font file

java.lang.NullPointerException
at com.sun.t2k.T2KFontFactory.getFontResourceByFileName(T2KFontFactory.java:485)
at com.sun.t2k.T2KFontFactory.getFontResource(T2KFontFactory.java:423)
at com.sun.t2k.FallbackResource.getSlotResource(FallbackResource.java:168)
at com.sun.t2k.T2KCompositeFontResource.getSlotResource(T2KCompositeFontResource.java:50)
at com.sun.t2k.CompositeGlyphMapper.getSlotMapper(CompositeGlyphMapper.java:52)
at com.sun.t2k.CompositeGlyphMapper.convertToGlyph(CompositeGlyphMapper.java:73)
at com.sun.t2k.CompositeGlyphMapper.getGlyphCode(CompositeGlyphMapper.java:129)
at com.sun.t2k.CharToGlyphMapper.charToGlyph(CharToGlyphMapper.java:116)
at com.sun.t2k.CompositeStrike.getCharAdvance(CompositeStrike.java:183)
at com.sun.webpane.sg.prism.WCFontImpl.getGlyphWidth(WCFontImpl.java:140)
at com.sun.webpane.platform.WebPage.twkUpdateContent(Native Method)
at com.sun.webpane.platform.WebPage.updateDirty(WebPage.java:366)
at com.sun.webpane.platform.WebPage.updateContent(WebPage.java:632)
at com.sun.javafx.sg.prism.NGWebView.update(NGWebView.java:52)
at javafx.scene.web.WebView.handleStagePulse(WebView.java:562)
at javafx.scene.web.WebView.access$100(WebView.java:55)
at javafx.scene.web.WebView$2.pulse(WebView.java:165)
at com.sun.javafx.tk.Toolkit.firePulse(Toolkit.java:289)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:398)
at com.sun.javafx.tk.quantum.QuantumToolkit$10.run(QuantumToolkit.java:330)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.access$100(WinApplication.java:29)
at com.sun.glass.ui.win.WinApplication$2$1.run(WinApplication.java:62)
at java.lang.Thread.run(Unknown Source)