Invalid data error reading pass **********. Manifest signature did not verify successfully. Could you please tell what this error could mean?
Looking at your pass, I note the following:
error 14:17:17.882524 +0700 Pass Viewer Invalid data error reading pass pass.com.xxxxx.xxxxxxxxxcard/0606. Manifest signature did not verify successfully
Looking at your pass contents, it is obvious why the signature did not verify. The signature file is empty:
-rwxr-xr-x@ 5685 Mar 16 14:55 icon.png
-rwxr-xr-x@ 7758 Mar 16 14:55 icon@2x.png
-rwxr-xr-x@ 5149 Mar 16 14:55 logo.png
-rwxr-xr-x@ 10693 Mar 16 14:55 logo@2x.png
-rwxr-xr-x@ 391 Mar 16 14:55 manifest.json
-rwxr-xr-x@ 228 Mar 16 14:55 pass.json
-rwxr-xr-x@ 0 Mar 16 14:55 signature
-rwxr-xr-x@ 20388 Mar 16 14:55 strip.png
-rwxr-xr-x@ 26843 Mar 16 14:55 strip@2x.png
The SHA hashes in the manifest check out ok, so this points to a problem with your signing code. You mentioned that you extract the private key. This could be part of your problem, since without a key, you cannot sign the pass.
But with no code, it is absolutely impossible to speculate any more than this.