Any idea why i lost those nice looking planes from my PiAware MLAT.
don’t know - but my mlat is down too 
I just installed it awhile ago and all of sudden MLAT is gone…
what do you get with:
cat /tmp/piaware.out
I am also feeding adsbExchange since its start (about a month ago?), and never lost MLAT Planes on my dump1090’s gmap.html. However VRS map at feed.adsbExchange.com often misses MLAT for some period, then starts showing the MLAT planes again.
probably this was just because of: http://discussions.flightaware.com/ads-b-flight-tracking-f21/fa-down-certificate-validation-failed-certificate-expired-t36424.html - that’s why i asked him for his piaware log …
Was late reading this. But anyway thanks for the responses guys. I now have a freshly formatted/installed all the needed software for all feeders.
i’d encourage you to make an image from your fresh and all setup sd-card - to be prepared if something goes wrong in future 
yep. I will . i appreciate your input guys.