KINME nodes not executing - unable to load class 'org.knime.product.rcp.addons'

Dear all,

I have a KNIME workflow that was working until today where I got an error preventing the flow to be executed.

Error log says

"unable to load class org.knime.product.rcp.addons.ToolbarFixAddon from bundle ‘1026’

Anyone encountered similar issue and understands root cause and/or how to fix ?

Thanks much

Marc