Hi,I encountered this problem on idea 2021.1.1 version.
com.intellij.diagnostic.PluginException: org.intellij.images.editor.actions.SetBackgroundImageAction PluginClassLoader(plugin=PluginDescriptor(name=Background Image Plus, id=co.notime.intellijPlugin.backgroundImagePlus, descriptorPath=plugin.xml, path=~\AppData\Roaming\JetBrains\IntelliJIdea2021.1\plugins\backgroundImagePlus.jar, version=1.2.1, package=null), packagePrefix=null, instanceId=12, state=active)
at com.intellij.openapi.actionSystem.impl.ActionManagerImpl.instantiate(ActionManagerImpl.java:250)
at com.intellij.openapi.actionSystem.impl.ActionManagerImpl.convertStub(ActionManagerImpl.java:220)
at com.intellij.openapi.actionSystem.impl.ActionManagerImpl.getActionImpl(ActionManagerImpl.java:551)
at com.intellij.openapi.actionSystem.impl.ActionManagerImpl.preloadActions(ActionManagerImpl.java:1601)
at com.intellij.openapi.actionSystem.impl.ActionPreloader.preload(ActionPreloader.java:14)
at com.intellij.openapi.application.Preloader.lambda$preload$0(Preloader.java:84)
at com.intellij.openapi.progress.impl.CoreProgressManager.lambda$runProcess$2(CoreProgressManager.java:178)
at com.intellij.openapi.progress.impl.CoreProgressManager.registerIndicatorAndRun(CoreProgressManager.java:688)
at com.intellij.openapi.progress.impl.CoreProgressManager.executeProcessUnderProgress(CoreProgressManager.java:634)
at com.intellij.openapi.progress.impl.ProgressManagerImpl.executeProcessUnderProgress(ProgressManagerImpl.java:64)
at com.intellij.openapi.progress.impl.CoreProgressManager.runProcess(CoreProgressManager.java:165)
at com.intellij.openapi.application.Preloader.lambda$preload$1(Preloader.java:74)
at com.intellij.util.concurrency.BoundedTaskExecutor.doRun(BoundedTaskExecutor.java:216)
at com.intellij.util.concurrency.BoundedTaskExecutor.access$200(BoundedTaskExecutor.java:27)
at com.intellij.util.concurrency.BoundedTaskExecutor$1.execute(BoundedTaskExecutor.java:195)
at com.intellij.util.ConcurrencyUtil.runUnderThreadName(ConcurrencyUtil.java:213)
at com.intellij.util.concurrency.BoundedTaskExecutor$1.run(BoundedTaskExecutor.java:184)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at java.base/java.util.concurrent.Executors$PrivilegedThreadFactory$1$1.run(Executors.java:668)
at java.base/java.util.concurrent.Executors$PrivilegedThreadFactory$1$1.run(Executors.java:665)
at java.base/java.security.AccessController.doPrivileged(Native Method)
at java.base/java.util.concurrent.Executors$PrivilegedThreadFactory$1.run(Executors.java:665)
at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: java.lang.ClassNotFoundException: org.intellij.images.editor.actions.SetBackgroundImageAction PluginClassLoader(plugin=PluginDescriptor(name=Background Image Plus, id=co.notime.intellijPlugin.backgroundImagePlus, descriptorPath=plugin.xml, path=~\AppData\Roaming\JetBrains\IntelliJIdea2021.1\plugins\backgroundImagePlus.jar, version=1.2.1, package=null), packagePrefix=null, instanceId=12, state=active)
at com.intellij.ide.plugins.cl.PluginClassLoader.loadClass(PluginClassLoader.java:215)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522)
at java.base/java.lang.Class.forName0(Native Method)
at java.base/java.lang.Class.forName(Class.java:398)
at com.intellij.openapi.actionSystem.impl.ActionManagerImpl.instantiate(ActionManagerImpl.java:233)
... 23 more
Hi,I encountered this problem on idea 2021.1.1 version.