I use BlueHost for webhosting. Just uploaded the current release to BH and cannot open the /zenphoto/zp-core/setup.php file. Getting 500 Error. Checked logs and no references to zenphoto. Not sure where to go from here.

This is an internal server error. You say no references to Zenphoto, but any related to that 500 error?

Is the file really there? The first to look is for file/folder permission being wrong or just too strict or the wrong owner of the files. Sometimes ftp clients mess around when uploading. Take a look here if that helps: https://www.zenphoto.org/news/permissions-for-zenphoto-files-and-folders/

Thanks for the reply. Since this is a shared hosting service, I cannot set the group to www-data (or equivalent). I have to set the perms on "world". Will that make a diff?

Also, there is no cache/ or cache_html/ folder in my archive.

The file owner must be the one that runs the PHP process. On some hosts the owner you upload via ftp is a different one. But permissions was just a guess, I have no knowledge about your host. Maybe ask your host's support.

The cache folder will be created once image sizes are generated. You didn't get that far yet sadly.
The cache_html folder is from the static_html_cache plugin and does not exist unless you use that plugin.

Well, all of my other php sites are running fine, so there must be something else.

Could you please try the support build (master) from GitHub?

Sure, I will give that a try. I also tried a local install on my development laptop and when I copy the folder and set perms, I get an "xdg-open" message. If I click "Open" then I get an error notification (https://imagebin.ca/v/4IjBAzOJMHPY)

I seem to be getting the setup page now with my perms/issues and sql information.

Yep, that indeed is an error in 1.5 I somehow yesterday forgot we fixed already. It only affects fresh installs as far as we know. Thanks for confirming it works for you as well which means 1.5.1 will soon follow.

So the setup runs for the most part, but I cannot get the mysqli information to return success. I have verified that the username/password/dbname I am using are correct by connecting at cli but the setup.php is not accepting it.

mysql> show databases;
+---------------------------+
| Database |
+---------------------------+
| information_schema |
| knichelo_zenphoto |
+---------------------------+
2 rows in set (1.43 sec)

Got it working, sorry to bother. Checking it out now.