Hi,
I have created a managed package. This package I installed in a test org successfully.
After that, I have implemented a "Post Install Script". Now it is impossible to install the package.
Even removing "Post Install Script" configuration does not have any affects.
I'm not able to delete the corresponding class. But I commented out all of the functions.
No luck. I still get an error email trying to install new package.

Any ideas?
Thank for reply in advance !

That's the class:

global class PostInstallScript implements InstallHandler {
    // start after installation methods
    global void onInstall(InstallContext context) {
        if(context.previousVersion() == null)
            startNewInstallation();

        // if(context.previousVersion().compareTo(new Version(1,0)) == 0)
        if(context.isUpgrade())
            startUpgrade();
        // if(context.isPush())
    }

    global void startNewInstallation(){
        writeVersionNumber();
    }
   
    global void startUpgrade(){
        writeVersionNumber();
    }

    private static void writeVersionNumber(){
    /*  no code  */
    }
}

Your request to install package "xyz" was unsuccessful. None of the data or setup information in your salesforce.com organization was affected.

If your install continues to fail, contact Salesforce CRM Support through your normal channels and provide the following information.

Organization: abc (00D24000000ZrBi)
User: Oleg Tuchscherer (00524000000HCj8)
Package: def (04tU00000001X9G)
Error Number: 575363182-26761 (-1283512546)

Package Install Failed

An error has occurred during a package install operation.