I\'m using IntelliJ IDE, I have installed google cloud sdk, google app engine sdk, python. but when I\'m trying to go through ItelliJ>>tools>>google app engine for php >> up
I got a similar error (on linux) when trying to run the development server after upgrading the GAE SDK from 1.9.49 (which worked fine) to currently latest 1.9.51.
After digging on SO and finding suggestions for renaming/removing the cacerts.txt file equivalent to the one you mentioned I tried it, but it didn't help - some other related error popped up.
So I just copied over the respective cacerts.txt file from the 1.9.49 SDK and things are working fine again.