IntelliJ IDEA版本信息：
IntelliJ IDEA 2021.2 (Ultimate Edition) Build #IU-212.4746.92, built on July 27, 2021 Licensed to XXXXXX Subscription is active until August 15, 2021. Runtime version: 11.0.11+9-b1504.13 amd64 VM: OpenJDK 64-Bit Server VM by JetBrains s.r.o. Linux 5.4.0-80-generic GC: G1 Young Generation, G1 Old Generation Memory: 2048M Cores: 3 Kotlin: 212-1.5.10-release-IJ4746.92 Current Desktop: X-Cinnamon
报错信息：
Abnormal build process termination: /usr/lib/jvm/java-1.8.0-openjdk-amd64/bin/java -Xmx700m -Djava.awt.headless=true -Djava.endorsed.dirs=\"\" -Dcompile.parallel=false -Drebuild.on.dependency.change=true -Djdt.compiler.useSingleThread=true -Daether.connector.resumeDownloads=false -Dio.netty.initialSeedUniquifier=-5972351880001011455 -Dfile.encoding=UTF-8 -Duser.language=en -Duser.country=US -Didea.paths.selector=IntelliJIdea2021.2 -Didea.home.path=/home/pm/idea-IU-212.4746.92 -Didea.config.path=/home/pm/.config/JetBrains/IntelliJIdea2021.2 -Didea.plugins.path=/home/pm/.local/share/JetBrains/IntelliJIdea2021.2 -Djps.log.dir=/home/pm/.cache/JetBrains/IntelliJIdea2021.2/log/build-log -Djps.fallback.jdk.home=/home/pm/idea-IU-212.4746.92/jbr -Djps.fallback.jdk.version=11.0.11 -Dio.netty.noUnsafe=true -Djava.io.tmpdir=/home/pm/.cache/JetBrains/IntelliJIdea2021.2/compile-server/rfg-survey-api_cc70fc05/_temp_ -Djps.backward.ref.index.builder=true -Djps.track.ap.dependencies=false --add-opens=jdk.compiler/com.sun.tools.javac.code=ALL-UNNAMED --add-opens=jdk.compiler/com.sun.tools.javac.comp=ALL-UNNAMED --add-opens=jdk.compiler/com.sun.tools.javac.file=ALL-UNNAMED --add-opens=jdk.compiler/com.sun.tools.javac.main=ALL-UNNAMED --add-opens=jdk.compiler/com.sun.tools.javac.model=ALL-UNNAMED --add-opens=jdk.compiler/com.sun.tools.javac.parser=ALL-UNNAMED --add-opens=jdk.compiler/com.sun.tools.javac.processing=ALL-UNNAMED --add-opens=jdk.compiler/com.sun.tools.javac.tree=ALL-UNNAMED --add-opens=jdk.compiler/com.sun.tools.javac.util=ALL-UNNAMED --add-opens=jdk.compiler/com.sun.tools.javac.jvm=ALL-UNNAMED -Dtmh.instrument.annotations=true -Dtmh.generate.line.numbers=true -Dkotlin.incremental.compilation=true -Dkotlin.incremental.compilation.js=true -Dkotlin.daemon.enabled -Dkotlin.daemon.client.alive.path=\"/tmp/kotlin-idea-12426594439704512301-is-running\" -classpath /home/pm/idea-IU-212.4746.92/plugins/java/lib/jps-launcher.jar:/usr/lib/jvm/java-1.8.0-openjdk-amd64/lib/tools.jar org.jetbrains.jps.cmdline.Launcher /home/pm/idea-IU-212.4746.92/lib/slf4j.jar:/home/pm/idea-IU-212.4746.92/lib/idea_rt.jar:/home/pm/idea-IU-212.4746.92/lib/platform-api.jar:/home/pm/idea-IU-212.4746.92/plugins/java/lib/maven-resolver-transport-file-1.3.3.jar:/home/pm/idea-IU-212.4746.92/lib/forms_rt.jar:/home/pm/idea-IU-212.4746.92/lib/util.jar:/home/pm/idea-IU-212.4746.92/lib/annotations.jar:/home/pm/idea-IU-212.4746.92/lib/3rd-party.jar:/home/pm/idea-IU-212.4746.92/lib/kotlin-stdlib-jdk8.jar:/home/pm/idea-IU-212.4746.92/plugins/java/lib/maven-resolver-connector-basic-1.3.3.jar:/home/pm/idea-IU-212.4746.92/lib/jna-platform.jar:/home/pm/idea-IU-212.4746.92/lib/protobuf-java-3.15.8.jar:/home/pm/idea-IU-212.4746.92/plugins/java/lib/jps-builders-6.jar:/home/pm/idea-IU-212.4746.92/plugins/java/lib/javac2.jar:/home/pm/idea-IU-212.4746.92/plugins/java/lib/aether-dependency-resolver.jar:/home/pm/idea-IU-212.4746.92/plugins/java/lib/jps-builders.jar:/home/pm/idea-IU-212.4746.92/plugins/java/lib/jps-javac-extension-1.jar:/home/pm/idea-IU-212.4746.92/lib/jna.jar:/home/pm/idea-IU-212.4746.92/lib/jps-model.jar:/home/pm/idea-IU-212.4746.92/plugins/java/lib/maven-resolver-transport-http-1.3.3.jar:/home/pm/idea-IU-212.4746.92/plugins/JavaEE/lib/jasper-v2-rt.jar:/home/pm/idea-IU-212.4746.92/plugins/Kotlin/lib/kotlin-reflect.jar:/home/pm/idea-IU-212.4746.92/plugins/Kotlin/lib/kotlin-plugin.jar:/home/pm/idea-IU-212.4746.92/plugins/ant/lib/ant-jps.jar:/home/pm/idea-IU-212.4746.92/plugins/uiDesigner/lib/jps/java-guiForms-jps.jar:/home/pm/idea-IU-212.4746.92/plugins/eclipse/lib/eclipse-jps.jar:/home/pm/idea-IU-212.4746.92/plugins/eclipse/lib/eclipse-common.jar:/home/pm/idea-IU-212.4746.92/plugins/IntelliLang/lib/java-langInjection-jps.jar:/home/pm/idea-IU-212.4746.92/plugins/Groovy/lib/groovy-jps.jar:/home/pm/idea-IU-212.4746.92/plugins/Groovy/lib/groovy-constants-rt.jar:/home/pm/idea-IU-212.4746.92/plugins/maven/lib/maven-jps.jar:/home/pm/idea-IU-212.4746.92/plugins/gradle-java/lib/gradle-jps.jar:/home/pm/idea-IU-212.4746.92/plugins/devkit/lib/devkit-jps.jar:/home/pm/idea-IU-212.4746.92/plugins/javaFX/lib/javaFX-jps.jar:/home/pm/idea-IU-212.4746.92/plugins/javaFX/lib/javaFX-common.jar:/home/pm/idea-IU-212.4746.92/plugins/JavaEE/lib/javaee-jps.jar:/home/pm/idea-IU-212.4746.92/plugins/webSphereIntegration/lib/jps/javaee-appServers-websphere-jps.jar:/home/pm/idea-IU-212.4746.92/plugins/weblogicIntegration/lib/jps/javaee-appServers-weblogic-jps.jar:/home/pm/idea-IU-212.4746.92/plugins/JPA/lib/jps/javaee-jpa-jps.jar:/home/pm/idea-IU-212.4746.92/plugins/Grails/lib/groovy-grails-jps.jar:/home/pm/idea-IU-212.4746.92/plugins/Grails/lib/groovy-grails-compilerPatch.jar:/home/pm/idea-IU-212.4746.92/plugins/Kotlin/lib/jps/kotlin-jps-plugin.jar:/home/pm/idea-IU-212.4746.92/plugins/Kotlin/lib/kotlin-jps-common.jar:/home/pm/idea-IU-212.4746.92/plugins/Kotlin/lib/kotlin-common.jar org.jetbrains.jps.cmdline.BuildMain 127.0.0.1 34781 9f0681bb-da2a-48db-8344-900ddeb29804 /home/pm/.cache/JetBrains/IntelliJIdea2021.2/compile-server Unrecognized option: --add-opens=jdk.compiler/com.sun.tools.javac.code=ALL-UNNAMED Error: Could not create the Java Virtual Machine. Error: A fatal exception has occurred. Program will exit.
问题原因：
Intellij IDEA 更新后一些配置在更新中被替换。"Project language level" 被从8升级成16 。
解决方法：
点击菜单中 "File" =》"Project Structure" =》"Project Settings" =》Project中，找到"Project language level"，然后将16改成8，则可以解决问题。