I installed the Grav Core + Admin Plugin on a Bluehost shared account. I experienced the following issues:
[I used the method of uploading and extracting the zip files.]
Bluehost is not happy with directories with 775 permission - I had to chmod them all to 755
Bluehost is not happy with files with 664 permission - I had to chmod them all to 644
(I used PuTTY SSH with the command “find /your/path/here -type d -exec chmod 755 {} ;” for changing all the directory permissions and “find /your/path/here -type f -exec chmod 644 {} ;” for changing all the file permissions.)
I still had no success. I then copied an older version of the index.php file from an older working instance of Grav that I have. I showed up the error. My php version was too low. I need to point out here that the index.php that comes with the latest download just did not run - I think it does not catch the error of the php version early enough.
I could configure my php version on Bluehost to ver 5.6. After that I changed the index.php back to the latest one. This time: SUCCESS!
I hope my experiences can help others trying to install Grav on shared hosts.