Package does not exist in this plugin

I tried importing a plugin as a source project in my workspace. Now I am getting a package does not exist in this plugin error in the Manifest.mf file. But the packages do exist in the source folder of the same plugin. What could be the issue? I tried googling but I could find only these kind of errors when the package is coming from a different eclipse project. Pls give me some light on this

https://i.sstatic.net/g2lrE.png

  Manifest-Version: 1.0
Bundle-ManifestVersion: 2
Bundle-Name: xyz Plug-in 2.1.0
Bundle-SymbolicName: com.abc.xyz
Bundle-Version: 2.1.0
Bundle-ClassPath: xyz.jar
Bundle-Activator: com.abc.xyz.xyzPlugin
Bundle-Vendor: FHG
Bundle-Localization: plugin
Export-Package: xyz.common,
 xyz.common.pattern,
 xyz.cursor,
 xyz.dm.common,
 xyz.dom,
 xyz.dom.bootModel,
 xyz.dom.exception,
 xyz.dom.x,
 xyz.errmsg,
 xyz.eventHandling,
 xyz.mof,
 xyz.mof.exception,
 xyz.mof.x,
 xyz.versioning.extent,
 xyz.versioning.versionstore,
 com.CH_co.cryptx,
 com.CH_co.util,
 com.abc.xyz,
 com.abc.xyz.uuid,
 com.tools,
 config,
 mdd.delta.model,
 mdd.diffmerge,
 mdd.diffmerge.event,
 mdd.model,
 transactionHandling,
 uuidGenerator
Eclipse-AutoStart: true
Require-Bundle: org.eclipse.core.runtime,
 com.abc.mdd.common

This is the manifest.mf file

The answer I found was a bit strange and I am unable to find the logic behind it. I deleted the errors in the Problems view and restarted the eclipse in clean mode. It started working. Pls let me know what could be the reason behind it