I recently upgraded the firmware on my ISY994i from 4.9.0 to 5.3.4.

Everything was working fine until I tried to replace a broken 6 button keypad with an 8-button keypad.  I keep getting the error message saying there is a problem with the insteon engine.  I have madee sure my java is up to date and have cleared the java cache including the applications and programs.

I would very much appreciate any help you can give me.  Thank you  

When you use the "replace with" function, for an Insteon device it must be like for like, i.e. 6 button with a 6 button.

You'll need to install the 8 button as a new device and delete the 6 button from the ISY.

Any programs, and scenes that were used by the 6 button KPL will have to be reprogrammed to include the new 8 button KPL.

I only have 8-button remotes so couldn’t say for sure but the suggestion to install the 8-button device was going to me my suggestion before I saw it given by someone else.  Some changes like 6 to 8 can be painful.  

Thanks for the response.  I did delete the 6 button and was trying to add the 8 button.  I kept getting the insteon engine error.

The error you're getting is usually caused by one of two things, poor communications between the device and the PLM or you entered an incorrect 6 digit address. It's easy to misread 8 and B, D and 0, etc.

Thanks to all who responded to my inquiry.  The situation is now resolved and the new keypadlinc is working correctly.

thanks