Had a problem saying “Installer information on recovery server is corrupted” when trying to reinstall MacOS (Sierra) on Macbook Air 2017. Most tutorials/”fixes” on Youtube/internet tell me that change my system date to like 2018, which fixes nothing..
The exact error in the installation log tells me the following:
Failed to open OSInstaller because the installer is not trusted: Error Domain=PKProductErrorDomain Code=0 "(null)" UserInfo={PKTrustlLevel=3, NSUnderlyingError=0x7f9d65522950 {Error Domain=NSOSStatusErrorDomain Code=-2147409654 "CSSMERR_TP_CERT_EXPIRED" UserInfo={SecTrustResult=5, PKTrustLevel=PKTrustLevelExpiredCertificate, NSLocalizedFailureReason=CSSMERR_TP_CERT_EXPIRED}}}
If anyone has experience with this or an idea how to fix this, please let me know.