I successfully get into the installation and it begins without any errors. Once it begins, it quickly hangs. The log shows it chrashes. I think this is the relevant text:
El Capitan Installation Hangs with Crash Report
Jul 2 18:51:51 iMac ReportCrash[513]: Thread 4 Crashed:
Jul 2 18:51:51 iMac ReportCrash[513]: 0 com.apple.CoreFoundation 0x000000010e41b696 CFDictionaryGetValue + 38
Jul 2 18:51:51 iMac ReportCrash[513]: 1 com.apple.MediaKit 0x000000010eb7cb8d GPTCFUpdateSection + 1060
Jul 2...
Jul 2 18:51:51 iMac ReportCrash[513]: 0 com.apple.CoreFoundation 0x000000010e41b696 CFDictionaryGetValue + 38
Jul 2 18:51:51 iMac ReportCrash[513]: 1 com.apple.MediaKit 0x000000010eb7cb8d GPTCFUpdateSection + 1060
Jul 2...
El Capitan Installation Hangs with Crash Report