For now three of my apps on Google Play I had a signing error like this when trying to upload a new version in the last few days:
Upload failed You uploaded an APK that is signed with a different certificate to your previous APKs. You must use the same certificate. Your existing APKs are signed with the certificate(s) with fingerprint(s):
[ SHA1: 87:17:A3:71:CD:CF:D6:73:71:56:B1:59:DE:89:6D:5A:E0:EE:31:8A,SHA1: 4C:45:1E:30:2D:04:F4:DC:36:0E:EF:29:1B:1E:E1:02:C0:E8:E9:85 ]
and the certificate(s) used to sign the APK you uploaded have fingerprint(s):
[ SHA1: 87:17:A3:71:CD:CF:D6:73:71:56:B1:59:DE:89:6D:5A:E0:EE:31:8A ]
I double-checked the keystore and it is the one I always used. In fact some of the apps have a pro version that use the same keystore and there the update worked fine. What is striking IMO is the strange fingerprint of the old, existing APK, which in the above case has a second entry with "SHA1:" in it and for one of the other apps that failed the old fingerprint was listed as "[ ]", i.e. an empty one. In the meantime I also updated other apps and in most cases things worked fine. The only thing (I noticed), which the three apps where I have problems with have in common, is that these apps are quite old, with the first APK version dating from 2009 or even 2008. But the pro versions - where things work fine - were introduced later.
There is a similar question Upload failed for newer version apk on google play, but the browser cache solution does not work and I am also quite confident that I used the right key.
Anyone have an idea what might be the solution here? I am starting to think that perhaps for some older apps the fingerprints were incorrectly extracted from the APKs on Google's side (hence the one empty and the other IMO a bit strange fingerprints for old versions). But typically problems originate from between one's own ears...
Thanks