java - Plug-in com.android.ide.eclipse.adt was unable to load class android

Question

I am new to android development My eclipse was working properly. But now when I start a new project it give an error Problem opening wizard The selected wizard could not be opened

The Detailed error message is

The selected wizard could not be started.
Plug-in com.android.ide.eclipse.adt was unable to load class com.android.ide.eclipse.adt.internal.wizards.newproject.NewProjectWizard.
An error occurred while automatically activating bundle com.android.ide.eclipse.adt (239).

I can't run existing Android project also.But I can start a new java project and run. Why this is happening

Answer 1

If you have not added ADT then do the Following steps.

Help -> Add New Software -> Add.

In Name option write ADT

And if you have installed ADT in your Computer then add its path in Location like

jar:file:/D:/ADT-16.0.1.zip!/

And then ADT will install.

And if there is a problem try to remove that adt and install again.

1) remove the ADT repo (Window->Preferences->Install/Updates->Available Software Sites)
2) add Indigo repo ("http://download.eclipse.org/releases/indigo")
3) run updates
4) add ADT repo again and install