How to solve this problem, please help:
More detail, please view this image: detail image
How to solve this problem, please help:
More detail, please view this image: detail image
It appears that your certificate has expired, assuming your clock is correctly set on your machine. Open the keychain access application and view the details of the certificate you generated on the developer portal. If the certificate is expired, then you need to create a new one from the portal, download and install it on your machine. Then, you will need to modify in your project settings the identity signing the code to reflect your new certificate.