Snoopie it should, but there was an update 38.0.5 that came out as well: Please update to the most recent version of Firefox:

• Update Firefox to the latest release

I have updated to Firefox 38.0.5 also downloaded the latest Citi Virtual Account Numbers. The program will still not "Auto-fill". Firefox add-ons tells me Virtual Account Numbers 4.0 not compatible with Firefox 38.0.5

I have updated to Firefox 38.0.5 also downloaded the latest Citi Virtual Account Numbers. The program will still not "Auto-fill". Firefox add-ons tells me Virtual Account Numbers 4.0 not compatible with Firefox 38.0.5

Any error messages from this extension in the Browser Console (Firefox/Tools > Web Developer)?

• https://developer.mozilla.org/Tools/Browser_Console