Plug in compatibility

Can someone help me?

Please provide your Gradle configuration and plugin.xml content

For the second issue – check JavaDocs, it contains all the migration information you need.

<idea-plugin>
    <id>TheBlind.privateNotes</id>
    <name>Private Notes</name>
    <version>1.0</version>
    <vendor email="1043193478@qq.com" url="https://gitee.com/Lovxy">TheBlind</vendor>

    <description><![CDATA[
        You are still afraid to add "sensitive comments" to the project<br/>
        Is the source code a read-only file and can't add comments<br/>
       <li>Anywhere you want to add comments, press <em> Alt + enter </em> mouse out and click to save</li>
       <li>There are private comments. Press <em> Alt + enter </em> to edit and delete them</li>
       <br/>
       你还在为项目中不敢添加 "敏感注释"!<br/>
       源码是只读文件不能添加注释而烦恼吗？<br/>
       <li>在任何你想加注释的地方 按下<em>Alt + Enter</em>鼠标移出点击即可保存</li>
       <li>已有私人注释 按下<em>Alt + Enter</em>即可编辑和删除</li>
       <img src="https://gitee.com/Lovxy/private-notes/raw/master/doc/show.gif"/>
    ]]></description>


    <!-- please see https://www.jetbrains.org/intellij/sdk/docs/basics/getting_started/build_number_ranges.html for description -->
    <idea-version since-build="193.0"/>

    <!-- please see https://www.jetbrains.org/intellij/sdk/docs/basics/getting_started/plugin_compatibility.html
         on how to target different products -->
    <depends>com.intellij.modules.platform</depends>
    <extensions defaultExtensionNs="com.intellij">
        <!--intentionAction 相关-->
        <intentionAction>
            <className>com.theblind.privatenotes.action.AddNoteIntentionAction</className>
        </intentionAction>
        <intentionAction>
            <className>com.theblind.privatenotes.action.EditNoteIntentionAction</className>
        </intentionAction>
        <intentionAction>
            <className>com.theblind.privatenotes.action.DeleteNoteIntentionAction</className>
        </intentionAction>
        <intentionAction>
            <className>com.theblind.privatenotes.action.WrapNoteIntentionAction</className>
        </intentionAction>

        <!--行尾拓展-->
        <editor.linePainter implementation="com.theblind.privatenotes.core.listener.PrivateNotesEditorLinePainter"/>
        <!--config-->
        <applicationService
                serviceImplementation="com.theblind.privatenotes.core.service.impl.ConfigServiceImpl$ConfigPersistenceThroughIdea"/>

        <applicationConfigurable
                instance="com.theblind.privatenotes.ui.GonfigForm"/>

        <psi.treeChangeListener
                implementation="com.theblind.privatenotes.core.listener.PrivateNotesFileChangeListener"/>
    </extensions>

    <!--文件监听-->
    <projectListeners>
        <listener class="com.theblind.privatenotes.core.listener.PrivateNotesFileEditorManagerListener"
                  topic="com.intellij.openapi.fileEditor.FileEditorManagerListener"/>

        <listener class="com.theblind.privatenotes.core.listener.PrivateNotesBulkFileListener"
                  topic="com.intellij.openapi.vfs.newvfs.BulkFileListener"/>
    </projectListeners>

</idea-plugin>

Gradle is not used

Gradle setup is highly recommended. You may find more information about it in the Getting Started with Gradle article.

Which version of the IntelliJ SDK do you use in your project?

version   2020.2.4

I've spent too much time on plug-in release. Is there any simple way to solve this problem?

You should use the IJ SDK version equal to your since-build value.

This SDK should also be provided, not marked as compile – please double-check your module configuration.

This SDK should also be provided, not marked as compile – please double-check your module configuration.

What should I do? This is the first time I write a plug-in

Again – use Gradle, not the DevKit approach.

Going with your current state of the project, navigate to your project's settings and check the module's configuration.