attiny84 bootloader failure

Using Uno as ISP selecting attiny84 @ 8Mhz from tools menu, get the following errors:

Arduino: 1.6.5 (Windows 7), Board: "ATtiny84 (internal 8 MHz clock)"

Error while burning bootloader.

java.lang.NullPointerException

	at cc.arduino.packages.uploaders.SerialUploader.burnBootloader(SerialUploader.java:305)

	at processing.app.Editor$59.run(Editor.java:2578)

	at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)

	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756)

	at java.awt.EventQueue.access$500(EventQueue.java:97)

	at java.awt.EventQueue$3.run(EventQueue.java:709)

	at java.awt.EventQueue$3.run(EventQueue.java:703)

	at java.security.AccessController.doPrivileged(Native Method)

	at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)

	at java.awt.EventQueue.dispatchEvent(EventQueue.java:726)

	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)

	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)

	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)

	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)

	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)

	at java.awt.EventDispatchThread.run(EventDispatchThread.java:82) 

[code]

Have checked and rechecked wiring connections. All appear to be correct. Am stumped! Any help would be appreciated. Thanks.
                                                Brian

What core are you using?

What version of the IDE?

Do you have correct programmer and COM port selected?

DrAzzy,
Using Attiny84 core.
version 1.6.5 IDE.
Arduino Uno as ISP
com port 6 (with this particular Uno board)

There are a very large number of cores that support attiny84, forked from one of several base cores - so that tells me nothing. Please link to the core you're using.

DrAzzy,
I am easily confused but I will try and understand what you are asking me. Using the Arduino Uno as the ISP I have selected the Attiny84 at 8 Mhz to burn the bootloader. I believe that would be the second choice listing in your post, ATtiny core for x4/x5/x61/x7/x8 series. My original post has the error printout I got when I tried to initiate the burn bootloader. From there, I am lost as to what to do to fix this error. Thanks.
Brian

Before there would have been any option to choose the ATTiny84 board, you must have installed support for that board (this is the “core”).

Where did you get that core?

That’s not my attiny core you’re using, on mine the ATTiny84 board name looks very different.

DrAzzy,
In versions of the Arduino previous to 1.6.0 I believe, it was necessary to retrieve and paste board definitions in the library for the attiny chips. The current version I am using is version 1.6.5 and the board definitions are already included in the drop down box under tools. I do not know which cores are included other than selecting what is available in the drop down box. I have not used previous versions to bootload an Attiny84. However, I have used the previous and current versions to program an Attiny85 successfully with both. How would I go about identifying which Attiny84 core I have? Thanks.
Brian

It's probably whatever you installed for 1.6.0 - since cores and the like get installed in your sketchbook folder (ie, (user)/Documents/Arduino/hardware...), they are not removed when you update the IDE.