我帮助解决了以下问题:

进入帮助->软件更新，然后选择可用软件选项卡，然后单击管理站点按钮 使用Export按钮将站点导出到bookmarks.xml文件 在您最喜欢的文本编辑器中打开bookmarks.xml文件，并在任何缺少“/”的网站url后添加一个“/”或删除末尾。保存更改。 回到Eclipse中的Manage Sites窗口，选择所有的站点并单击Remove按钮 现在，单击Import并加载编辑过的bookmarks.xml文件

对于那些在安装Eclipse代码推荐器时遇到此问题的人，您可以尝试Eclipse社区论坛的建议:

Go to Help -> Install new software...
Add a repository: 
    Name: Code Recommenders
    Location: https://repo.eclipse.org/content/shadows/releases.unzip/org/eclipse/recommenders/stable/2.5.4/stable-2.5.4.zip-unzip/

我想这种方法也可以用于其他归档项目。

对我来说，我在Eclipse Oxygen上安装了Spring IDE。在检查更新期间，它将发现更新，然后它将失败，并出现上述错误。

然后我转到Eclipse市场，单击Installed选项卡，注意到Spring没有出现(它以前在那里，现在已经安装了)。

然后我搜索Spring IDE (Tools)，点击install，然后它通知一些包已经安装，只需要更新。

在完成Spring Tools的安装并重新启动后，我可以检查更新并完成正常的软件更新。

简单! !

右键单击eclipse文件夹并进入属性。 取消选中“只读”复选框。 应用更改。单击oK。

>安装新软件>取消勾选“安装期间联系所有更新站点以查找所需软件”。

求助→安装新软件→这里取消勾选“安装期间联系所有更新站点以查找所需软件”

Eclipse将提示内容未经授权或类似的内容。忽略它，继续。那么一切都会好的。

至少这个技巧解决了我类似这样的问题:

An error occurred while collecting items to be installed session
context was:(profile=epp.package.jee,
phase=org.eclipse.equinox.internal.p2.engine.phases.Collect, operand=,
action=). No repository found containing:
osgi.bundle,org.eclipse.emf,2.6.0.v20120917-0436 No repository found
containing: osgi.bundle,org.eclipse.emf.ant,2.7.0.v20120917-0436 No
repository found containing:
osgi.bundle,org.eclipse.emf.codegen,2.8.0.v20120917-0436 No repository
found containing:
osgi.bundle,org.eclipse.emf.codegen.ecore,2.8.1.v20120917-0436 No
repository found containing:
osgi.bundle,org.eclipse.emf.codegen.ecore.ui,2.8.0.v20120917-0436 No
repository found containing:
osgi.bundle,org.eclipse.emf.codegen.ui,2.6.0.v20120917-0436 No
repository found containing:
osgi.bundle,org.eclipse.emf.common,2.8.0.v20120911-0500 No repository
found containing:
osgi.bundle,org.eclipse.emf.common.ui,2.7.0.v20120917-0436 No
repository found containing:
osgi.bundle,org.eclipse.emf.converter,2.5.0.v20120917-0436 No
repository found containing:
osgi.bundle,org.eclipse.emf.databinding,1.2.0.v20120917-0436 No
repository found containing:
osgi.bundle,org.eclipse.emf.databinding.edit,1.2.0.v20120917-0436 No
repository found containing:
osgi.bundle,org.eclipse.emf.ecore,2.8.1.v20120911-0500 No repository
found containing:
osgi.bundle,org.eclipse.emf.ecore.change,2.8.0.v20120911-0500 No
repository found containing:
osgi.bundle,org.eclipse.emf.ecore.change.edit,2.5.0.v20120917-0436 No
repository found containing:
osgi.bundle,org.eclipse.emf.ecore.edit,2.8.0.v20120917-0436 No
repository found containing:
osgi.bundle,org.eclipse.emf.ecore.editor,2.8.0.v20120917-0436 No
repository found containing:
osgi.bundle,org.eclipse.emf.ecore.xmi,2.8.0.v20120911-0500 No
repository found containing:
osgi.bundle,org.eclipse.emf.edit,2.8.0.v20120917-0436 No repository
found containing:
osgi.bundle,org.eclipse.emf.edit.ui,2.8.0.v20120917-0436 No repository
found containing:
osgi.bundle,org.eclipse.emf.exporter,2.6.0.v20120917-0436 No
repository found containing:
osgi.bundle,org.eclipse.emf.importer,2.7.0.v20120917-0436 No
repository found containing:
osgi.bundle,org.eclipse.emf.importer.ecore,2.6.0.v20120917-0436 No
repository found containing:
osgi.bundle,org.eclipse.emf.importer.java,2.6.0.v20120917-0436 No
repository found containing:
osgi.bundle,org.eclipse.emf.importer.rose,2.6.0.v20120917-0436 No
repository found containing:
osgi.bundle,org.eclipse.emf.mapping,2.7.0.v20120917-0436 No repository
found containing:
osgi.bundle,org.eclipse.emf.mapping.ecore,2.6.0.v20120917-0436 No
repository found containing:
osgi.bundle,org.eclipse.emf.mapping.ecore.editor,2.6.0.v20120917-0436
No repository found containing:
osgi.bundle,org.eclipse.emf.mapping.ecore2ecore,2.7.0.v20120917-0436
No repository found containing:
osgi.bundle,org.eclipse.emf.mapping.ecore2ecore.editor,2.5.0.v20120917-0436
No repository found containing:
osgi.bundle,org.eclipse.emf.mapping.ecore2xml,2.7.0.v20120917-0436 No
repository found containing:
osgi.bundle,org.eclipse.emf.mapping.ecore2xml.ui,2.6.0.v20120917-0436
No repository found containing:
osgi.bundle,org.eclipse.emf.mapping.ui,2.6.0.v20120917-0436 No
repository found containing:
osgi.bundle,org.eclipse.wst.common.project.facet.core,1.4.300.v201111030424
No repository found containing:
osgi.bundle,org.eclipse.wst.common.project.facet.ui,1.4.300.v201111030424
No repository found containing:
org.eclipse.update.feature,org.eclipse.emf.codegen.ecore,2.8.1.v20120917-0436
No repository found containing:
org.eclipse.update.feature,org.eclipse.emf.codegen.ecore.ui,2.8.0.v20120917-0436
No repository found containing:
org.eclipse.update.feature,org.eclipse.emf.codegen,2.8.0.v20120917-0436
No repository found containing:
org.eclipse.update.feature,org.eclipse.emf.codegen.ui,2.7.0.v20120917-0436
No repository found containing:
org.eclipse.update.feature,org.eclipse.emf.common,2.8.0.v20120911-0500
No repository found containing:
org.eclipse.update.feature,org.eclipse.emf.common.ui,2.7.0.v20120917-0436
No repository found containing:
org.eclipse.update.feature,org.eclipse.emf.converter,2.8.0.v20120917-0436
No repository found containing:
org.eclipse.update.feature,org.eclipse.emf.databinding.edit,1.2.0.v20120917-0436
No repository found containing:
org.eclipse.update.feature,org.eclipse.emf.databinding,1.2.0.v20120917-0436
No repository found containing:
org.eclipse.update.feature,org.eclipse.emf.ecore.edit,2.8.0.v20120917-0436
No repository found containing:
org.eclipse.update.feature,org.eclipse.emf.ecore.editor,2.8.0.v20120917-0436
No repository found containing:
org.eclipse.update.feature,org.eclipse.emf.ecore,2.8.1.v20120911-0500
No repository found containing:
org.eclipse.update.feature,org.eclipse.emf.edit,2.8.0.v20120917-0436
No repository found containing:
org.eclipse.update.feature,org.eclipse.emf.edit.ui,2.8.0.v20120917-0436
No repository found containing:
org.eclipse.update.feature,org.eclipse.emf,2.8.1.v20120917-0436 No
repository found containing:
org.eclipse.update.feature,org.eclipse.emf.mapping.ecore.editor,2.7.0.v20120917-0436
No repository found containing:
org.eclipse.update.feature,org.eclipse.emf.mapping.ecore,2.7.0.v20120917-0436
No repository found containing:
org.eclipse.update.feature,org.eclipse.emf.mapping,2.7.0.v20120917-0436
No repository found containing:
org.eclipse.update.feature,org.eclipse.emf.mapping.ui,2.7.0.v20120917-0436
No repository found containing:
org.eclipse.update.feature,org.eclipse.wst.common.fproj,3.4.0.v201202292300-377F8N8s735555393B7B

我帮助解决了以下问题:

进入帮助->软件更新，然后选择可用软件选项卡，然后单击管理站点按钮 使用Export按钮将站点导出到bookmarks.xml文件 在您最喜欢的文本编辑器中打开bookmarks.xml文件，并在任何缺少“/”的网站url后添加一个“/”或删除末尾。保存更改。 回到Eclipse中的Manage Sites窗口，选择所有的站点并单击Remove按钮 现在，单击Import并加载编辑过的bookmarks.xml文件