openssl: PEM_read_bio_X509 returns Null

After I updated my openssl version from 1.0.2r to 1.1.1d of my iOS project , the function PEM_read_bio_X509 returns null. The following error is being printed in the console 4392048812:error:20068078:lib(32):func(104):reason(120):bio_lib.c:299: 4392048812:error:0906D06C:lib(9):func(109):reason(108):pem_lib.c:697: so that points to failures in pem_lib.c at line 697 and bio_lib.c at line 299, but looking at those files, it’s not clear what that means (there aren’t errors emitted at those lines).