Uncanny sporadic (whitespace?) error with Eclipse/Java?

I have been having very weird problems with coding Java in Eclipse (the error shown in fact affects execution so it might be Java error rather than Eclips). Basically a error appears out of the blue when working elsewhere on same class, different class or just randomly. The code is correct and does execute when error dissappears. To make it disappear I just need to copy and paste the same code a few times or add and delete spaces and then save. The hotsposts are lambdas, streams and some other expression. The length also varies: eg. bellow only .stream() or whole statement. Image error:enter image description here Image after copy and paste: enter image description here

Code: List allLines=null; try { Path path=Paths.get(filePath); allLines = Files.readAllLines(path); } catch (IOException e) { // TO-DO deal with exception – popup? e.printStackTrace(); } List filteredLines = allLines.stream() .map(String :: trim) .filter(line -> !line.equals(“”))
.collect(Collectors.toList());

Error: Exception in thread “JavaFX Application Thread” java.lang.RuntimeException: java.lang.reflect.InvocationTargetException at javafx.fxml/javafx.fxml.FXMLLoader$ MethodHandler.invoke(FXMLLoader.java:1787) at javafx.fxml/javafx.fxml.FXMLLoader$ ControllerMethodEventHandler.handle(FXMLLoader.java:1670) at javafx.base/com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86) at javafx.base/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238) at javafx.base/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191) at javafx.base/com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59) at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58) at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114) at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56) at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114) at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56) at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114) at javafx.base/com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74) at javafx.base/com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49) at javafx.base/javafx.event.Event.fireEvent(Event.java:198) at javafx.graphics/javafx.scene.Node.fireEvent(Node.java:8879) at javafx.controls/javafx.scene.control.Button.fire(Button.java:200) at javafx.controls/com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(ButtonBehavior.java:206) at javafx.controls/com.sun.javafx.scene.control.inputmap.InputMap.handle(InputMap.java:274) at javafx.base/com.sun.javafx.event.CompositeEventHandler$ NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218) at javafx.base/com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80) at javafx.base/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238) at javafx.base/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191) at javafx.base/com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59) at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58) at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114) at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56) at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114) at javafx.base/com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56) at javafx.base/com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114) at javafx.base/com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74) at javafx.base/com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54) at javafx.base/javafx.event.Event.fireEvent(Event.java:198) at javafx.graphics/javafx.scene.Scene$ MouseHandler.process(Scene.java:3851) at javafx.graphics/javafx.scene.Scene$ MouseHandler.access$ 1200(Scene.java:3579) at javafx.graphics/javafx.scene.Scene.processMouseEvent(Scene.java:1849) at javafx.graphics/javafx.scene.Scene$ ScenePeerListener.mouseEvent(Scene.java:2588) at javafx.graphics/com.sun.javafx.tk.quantum.GlassViewEventHandler$ MouseEventNotification.run(GlassViewEventHandler.java:397) at javafx.graphics/com.sun.javafx.tk.quantum.GlassViewEventHandler$ MouseEventNotification.run(GlassViewEventHandler.java:295) at java.base/java.security.AccessController.doPrivileged(Native Method) at javafx.graphics/com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$ handleMouseEvent$ 2(GlassViewEventHandler.java:434) at javafx.graphics/com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:390) at javafx.graphics/com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:433) at javafx.graphics/com.sun.glass.ui.View.handleMouseEvent(View.java:556) at javafx.graphics/com.sun.glass.ui.View.notifyMouse(View.java:942) at javafx.graphics/com.sun.glass.ui.win.WinApplication._runLoop(Native Method) at javafx.graphics/com.sun.glass.ui.win.WinApplication.lambda$ runLoop$ 3(WinApplication.java:174) at java.base/java.lang.Thread.run(Thread.java:834) Caused by: java.lang.reflect.InvocationTargetException at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:566) at com.sun.javafx.reflect.Trampoline.invoke(MethodUtil.java:76) at jdk.internal.reflect.GeneratedMethodAccessor2.invoke(Unknown Source) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:566) at javafx.base/com.sun.javafx.reflect.MethodUtil.invoke(MethodUtil.java:273) at javafx.fxml/com.sun.javafx.fxml.MethodHelper.invoke(MethodHelper.java:83) at javafx.fxml/javafx.fxml.FXMLLoader$ MethodHandler.invoke(FXMLLoader.java:1782) … 47 more Caused by: java.lang.Error: Unresolved compilation problem: The method stream() is undefined for the type List

at creators.ReaderPWM.read(ReaderPWM.java:50) at application.ControllerFX.readPWM(ControllerFX.java:134) at application.ControllerPWMFileChooser.read(ControllerPWMFileChooser.java:7) at application.ControllerFileChooser.submittedSet(ControllerFileChooser.java:145) ... 58 more