last night while deploying my GAE app, I got this error in terminal.
ERROR: (gcloud.app.deploy) INVALID_ARGUMENT: Your app may not have more than 15 versions. Please delete one of the existing versions before trying to create a new version.
there is a simple fix.
in your teminal you need to use:
gcloud app versions list
gcloud app versions delete v1 v2
Based on the version numbers, replace v1 and v2 in the example above with your actual version numbers from the output of the first script. My version numbers were 20+ character date time strings, but copying and pasting them in worked well.
Hopefully there is an easier way to delete all prev versions, but I haven’t found it yet.
It looks like Alastair has written a bash script to delete all but the last three versions here. I tried it out and it worked perfectly!