Projects fail to open on Intellij

Question

I just added some plugins to intellijIdea version 14.0.1, on restarting it, non of my projects could load.

This is the error message

Cannot load project: com.intellij.ide.plugins.PluginManager$StartupAbortedException: com.intellij.diagnostic.PluginException: Bad type on operand stack
Exception Details:
  Location:
    com/intellij/atg/jsp/OpenDspInclude.registerTags(Lcom/intellij/psi/PsiReferenceProvider;Ljava/lang/String;Lcom/intellij/psi/filters/position/NamespaceFilter;[Ljava/lang/String;)V @19: invokestatic
  Reason:
    Type 'com/intellij/psi/impl/source/resolve/reference/ReferenceProvidersRegistry' (current frame, stack[0]) is not assignable to 'com/intellij/psi/PsiReferenceRegistrar'
  Current Frame:
    bci: @19
    flags: { }
    locals: { 'com/intellij/atg/jsp/OpenDspInclude', 'com/intellij/psi/PsiReferenceProvider', 'java/lang/String', 'com/intellij/psi/filters/position/NamespaceFilter', '[Ljava/lang/String;' }
    stack: { 'com/intellij/psi/impl/source/resolve/reference/ReferenceProvidersRegistry', '[Ljava/lang/String;', 'com/intellij/psi/filters/ScopeFilter', 'com/intellij/psi/PsiReferenceProvider' }
  Bytecode:
    0000000: 2ab4 001c 04bd 0031 5903 2c53 2d19 04b8
    0000010: 004f 2bb8 0055 b1                      
 [Plugin: OpenDSPInclude]

Answer 1

You have installed plugins which are not compatible With IntelliJ. You have to uninstall them.

In my case, it was the Gradle Gui Plugin.

Answer 2

This can happen due to plugin incompatibility.
Please check if your intellij version is supported by plugin.
Meanwhile to get access to your projects you can disable the plugin.