1. The problem of the original installation package has been added with an indecipherable plug-in. At this time, you can go to the group and ask if there are similar IPA packages.
2. You have installed this app on your mobile phone (you often forget to install it, re sign and find that it can't be installed all the time. Just delete the previous one)
3. If the signature is unsuccessful, change the IPA package of the same type to ask the God in the group.
4. Under special circumstances, when you sign the certificate, you can use the recovery and verification function on the side of the certificate to select the status of all certificates to check whether the certificate is signed off.