以下是我试图解决这个问题的方法，它奏效了:

从.m2 repo中手动删除现有插件 在IntelliJ中启用“使用插件注册表” 使缓存无效并重新启动IntelliJ 在IntelliJ中重新导入maven项目

在执行上述步骤后，问题得到了修复。希望这对你也有帮助。

解决了! !

这就是我解决问题的方法……

Tried one of the answers which include 'could solve it by enabling "use plugin registry" '. Did enable that but no luck. Tried again one of the answers in the thread which says 'If that does not work, Invalidate your caches (File > Invalidate caches) and restart.' Did that but again no luck. Tried These options .. Go to Settings --> Maven --> Importing and made sure the following was selected Import Maven projects automatically Create IDEA modules for aggregator projects Keep source... Exclude build dir... Use Maven output... Generated souces folders: "detect automatically" Phase to be...: "process-resources" Automatically download: "sources" & "documentation" Use Maven3 to import project VM options for importer: -Xmx512m But again no success. Now lets say I had 10 such plugins which didn't get resolve and among them the first was 'org.apache.maven.plugins:maven-site-plugin' I went to '.m2/repository/org/apache/maven/plugins/' and deleted the directory 'maven-site-plugin' and did a maven reimport again. Guess what, particular missing plugin got dowloaded. And I just followed similar steps for other missing plugins and all got resolved.

Goto intelligent -> Preferences ->插件

搜索maven，你会看到 1. Maven集成 2. Maven集成扩展。

选择Maven Integration选项并重新启动Intellij

从maven工具窗口运行Force重新导入。如果不工作，Invalidate你的缓存(文件> Invalidate缓存)并重新启动。等待IDEA重新索引项目。

6月/ 2021:

不删除，不重新导入。

我所做的就是:

C:\Users\dell\.m2\repository\org\apache\maven\plugins

然后双击每个插件文件夹，并查看下载的版本。

然后我回到pom文件，根据下载的版本，我在<version>....中仔细修改了那些版本> < /版本标签。然后刷新。

这样，所有的红色标记都消失了，甚至那些黄色标记也消失了。

所有的清洁。

这是我完整的pom文件，以备进一步通知。该项目是JavaFx+Maven与阴影:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>main.java.sample</groupId>
    <artifactId>ThreeColumnTable</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>11</maven.compiler.source>
        <maven.compiler.target>11</maven.compiler.target>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.openjfx</groupId>
            <artifactId>javafx-controls</artifactId>
            <version>15.0.1</version>
        </dependency>
        <dependency>
            <groupId>org.openjfx</groupId>
            <artifactId>javafx-fxml</artifactId>
            <version>15.0.1</version>
        </dependency>
        <dependency>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-install-plugin</artifactId>
            <version>2.4</version>
            <type>maven-plugin</type>
        </dependency>

        <dependency>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-deploy-plugin</artifactId>
            <version>2.7</version>
            <type>maven-plugin</type>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.8.0</version>
                <configuration>
                    <source>11</source>
                    <target>11</target>
                    <release>11</release>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-resources-plugin</artifactId>
                <version>2.6</version>
                <executions>
                    <execution>
                        <phase>test</phase>
                        <goals>
                            <goal>resources</goal>
                            <goal>testResources</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-project-info-reports-plugin</artifactId>
                <version>3.1.2</version>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-clean-plugin</artifactId>
                <version>3.1.0</version>
                <configuration>
                    <filesets>
                        <fileset>
                            <directory>src/main/generated-groovy-stubs</directory>
                        </fileset>
                    </filesets>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-jar-plugin</artifactId>
                <version>2.4</version>
                <configuration>
                    <archive>
                        <manifest>
                            <mainClass>org.example.App</mainClass>
                            <manifestFile>src/main/resources/META-INF/MANIFEST.MF</manifestFile>
                        </manifest>
                    </archive>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.openjfx</groupId>
                <artifactId>javafx-maven-plugin</artifactId>
                <version>0.0.1</version>
                <configuration>
                    <mainClass>org.example.App</mainClass>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-shade-plugin</artifactId>
                <version>3.2.4</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>shade</goal>
                        </goals>
                        <configuration>
                            <shadedArtifactAttached>true</shadedArtifactAttached>
                            <shadedClassifierName>project-classifier</shadedClassifierName>
                            <transformers>
                                <transformer implementation=
                                                     "org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                                    <mainClass>org.example.Main</mainClass>
                                </transformer>
                            </transformers>

                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>

我的情况:

maven-javadoc-plugin with version 3.2.0 is displayed red in IntelliJ. Plugin is present in my local maven repo. Re-imported maven million times. Ran mvn clean install from the command line N times. All my maven settings in IntelliJ are correct. Tried to switch between Bundled and non-bundled Maven. Tried do delete the whole maven repo and to delete only the plugin from it. Nothing of the above worked. The only thing that almost always helps with modern IntelliJ IDEA versions is "Invalidate caches / Restart". It helped this time as well. maven-javadoc-plugin is not red anymore, and I can click on it and to to the source pom file of the plugin.