Exception: Light files should have PSI only in one project

Got this one too, this seems to happen, when multiple projects are opened in different windows.
java.lang.Throwable: Light files should have PSI only in one project, existing=com.intellij.psi.SingleRootFileViewProvider{vFile=LightVirtualFile: /Dummy.txt, content=VirtualFileContent{size=0}, eventSystemEnabled=true} in Project(name=..., containerState=COMPONENT_CREATED, componentStore=/Users/bric3/projects), requested in Project(name=other-project-in-other-window, containerState=COMPONENT_CREATED, componentStore=/Users/bric3/private/project)
    at com.intellij.openapi.diagnostic.Logger.error(Logger.java:159)
    at com.intellij.psi.impl.file.impl.FileManagerImpl.checkHasNoOtherPsi(FileManagerImpl.java:205)
    at com.intellij.psi.impl.file.impl.FileManagerImpl.findViewProvider(FileManagerImpl.java:194)
    at com.intellij.psi.impl.file.impl.FileManagerImpl.findFile(FileManagerImpl.java:368)
    at com.intellij.psi.impl.PsiDocumentManagerBase.getPsiFile(PsiDocumentManagerBase.java:142)
    at com.intellij.psi.impl.PsiDocumentManagerBase.getPsiFile(PsiDocumentManagerBase.java:93)
    at com.intellij.psi.impl.PsiDocumentManagerImpl.getPsiFile(PsiDocumentManagerImpl.java:64)
    at com.intellij.advancedExpressionFolding.AdvancedExpressionFoldingHighlightingComponent.mouseMoved(AdvancedExpressionFoldingHighlightingComponent.java:248)
    at jdk.internal.reflect.GeneratedMethodAccessor143.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 com.intellij.util.EventDispatcher.dispatchVoidMethod(EventDispatcher.java:123)
    at com.intellij.util.EventDispatcher.lambda$createMulticaster$1(EventDispatcher.java:86)
    at com.sun.proxy.$Proxy82.mouseMoved(Unknown Source)
    at com.intellij.openapi.editor.impl.EditorImpl$MyMouseMotionListener.mouseMoved(EditorImpl.java:4312)
    at java.desktop/java.awt.Component.processMouseMotionEvent(Component.java:6697)
    at java.desktop/javax.swing.JComponent.processMouseMotionEvent(JComponent.java:3363)
    at java.desktop/java.awt.Component.processEvent(Component.java:6421)
    at java.desktop/java.awt.Container.processEvent(Container.java:2263)
    at java.desktop/java.awt.Component.dispatchEventImpl(Component.java:5027)
    at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2321)
    at java.desktop/java.awt.Component.dispatchEvent(Component.java:4859)
    at java.desktop/java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4918)
    at java.desktop/java.awt.LightweightDispatcher.processMouseEvent(Container.java:4560)
    at java.desktop/java.awt.LightweightDispatcher.dispatchEvent(Container.java:4488)
    at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2307)
    at java.desktop/java.awt.Window.dispatchEventImpl(Window.java:2780)
    at java.desktop/java.awt.Component.dispatchEvent(Component.java:4859)
    at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:778)
    at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:727)
    at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:721)
    at java.base/java.security.AccessController.doPrivileged(Native Method)
    at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
    at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:95)
    at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:751)
    at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:749)
    at java.base/java.security.AccessController.doPrivileged(Native Method)
    at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
    at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:748)
    at com.intellij.ide.IdeEventQueue.defaultDispatchEvent(IdeEventQueue.java:973)
    at com.intellij.ide.IdeEventQueue.dispatchMouseEvent(IdeEventQueue.java:908)
    at com.intellij.ide.IdeEventQueue._dispatchEvent(IdeEventQueue.java:837)
    at com.intellij.ide.IdeEventQueue.lambda$dispatchEvent$8(IdeEventQueue.java:451)
    at com.intellij.openapi.progress.impl.CoreProgressManager.computePrioritized(CoreProgressManager.java:773)
    at com.intellij.ide.IdeEventQueue.lambda$dispatchEvent$9(IdeEventQueue.java:450)
    at com.intellij.openapi.application.impl.ApplicationImpl.runIntendedWriteActionOnCurrentThread(ApplicationImpl.java:822)
    at com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.java:504)
    at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
    at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
    at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
    at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
    at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
    at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)
cheptsov / AdvancedExpressionFolding

Exception: Light files should have PSI only in one project #145
