I'm also having server 500 errors. I will say that I'm not on a pi, but running ubuntu. The apache and php were not pi specific. I received no errors at all doing the install, and this is my screen capture, and it looks the same.
BTW, this is great, thanks for the work and your patience.
Can you post the contents of your /var/log/apache2/error.log?
[Wed Apr 11 17:40:50.868246 2018] [mpm_event:notice] [pid 2178:tid 140434742282112] AH00489: Apache/2.4.18 (Ubuntu) configured – resuming normal operations
[Wed Apr 11 17:40:50.868353 2018] [core:notice] [pid 2178:tid 140434742282112] AH00094: Command line: ‘/usr/sbin/apache2’
[Wed Apr 11 17:43:20.523400 2018] [mpm_event:notice] [pid 2178:tid 140434742282112] AH00491: caught SIGTERM, shutting down
[Wed Apr 11 17:43:21.624310 2018] [mpm_prefork:notice] [pid 8474] AH00163: Apache/2.4.18 (Ubuntu) configured – resuming normal operations
[Wed Apr 11 17:43:21.624439 2018] [core:notice] [pid 8474] AH00094: Command line: ‘/usr/sbin/apache2’
[Wed Apr 11 17:43:21.995074 2018] [mpm_prefork:notice] [pid 8474] AH00169: caught SIGTERM, shutting down
[Wed Apr 11 17:43:23.133900 2018] [mpm_prefork:notice] [pid 8581] AH00163: Apache/2.4.18 (Ubuntu) configured – resuming normal operations
[Wed Apr 11 17:43:23.133957 2018] [core:notice] [pid 8581] AH00094: Command line: ‘/usr/sbin/apache2’
[Wed Apr 11 17:47:40.463130 2018] [mpm_prefork:notice] [pid 8581] AH00169: caught SIGTERM, shutting down
[Wed Apr 11 17:47:41.589652 2018] [mpm_prefork:notice] [pid 8685] AH00163: Apache/2.4.18 (Ubuntu) configured – resuming normal operations
[Wed Apr 11 17:47:41.589709 2018] [core:notice] [pid 8685] AH00094: Command line: ‘/usr/sbin/apache2’
[Wed Apr 11 17:47:52.883751 2018] [core:alert] [pid 8688] [client 192.168.1.10:58808] /var/www/webcore/.htaccess: Invalid command ‘RewriteEngine’, perhaps misspelled or defined by a module not included in the server configuration
[Wed Apr 11 17:47:56.483842 2018] [core:alert] [pid 8689] [client 192.168.1.10:58809] /var/www/webcore/.htaccess: Invalid command ‘RewriteEngine’, perhaps misspelled or defined by a module not included in the server configuration
[Wed Apr 11 17:48:14.718147 2018] [core:alert] [pid 8691] [client 192.168.1.10:58828] /var/www/webcore/.htaccess: Invalid command ‘RewriteEngine’, perhaps misspelled or defined by a module not included in the server configuration
[Wed Apr 11 17:48:17.672047 2018] [core:alert] [pid 8692] [client 192.168.1.10:58829] /var/www/webcore/.htaccess: Invalid command ‘RewriteEngine’, perhaps misspelled or defined by a module not included in the server configuration
[Wed Apr 11 17:48:26.130888 2018] [core:alert] [pid 8688] [client 192.168.1.10:58833] /var/www/webcore/.htaccess: Invalid command ‘RewriteEngine’, perhaps misspelled or defined by a module not included in the server configuration
[Wed Apr 11 17:49:30.959614 2018] [core:alert] [pid 8689] [client 192.168.1.10:58933] /var/www/webcore/.htaccess: Invalid command ‘RewriteEngine’, perhaps misspelled or defined by a module not included in the server configuration
[Wed Apr 11 17:50:12.959327 2018] [core:alert] [pid 8690] [client 192.168.1.10:58942] /var/www/webcore/.htaccess: Invalid command ‘RewriteEngine’, perhaps misspelled or defined by a module not included in the server configuration
[Wed Apr 11 17:50:44.281302 2018] [core:alert] [pid 8691] [client 192.168.1.10:59009] /var/www/webcore/.htaccess: Invalid command ‘RewriteEngine’, perhaps misspelled or defined by a module not included in the server configuration
[Wed Apr 11 17:52:05.028865 2018] [core:alert] [pid 8692] [client 192.168.1.10:59090] /var/www/webcore/.htaccess: Invalid command ‘RewriteEngine’, perhaps misspelled or defined by a module not included in the server configuration
[Wed Apr 11 17:52:34.201011 2018] [core:alert] [pid 8688] [client 192.168.1.10:59141] /var/www/webcore/.htaccess: Invalid command ‘RewriteEngine’, perhaps misspelled or defined by a module not included in the server configuration
[Wed Apr 11 17:52:43.855961 2018] [mpm_prefork:notice] [pid 8685] AH00169: caught SIGTERM, shutting down
[Wed Apr 11 17:52:44.983285 2018] [mpm_prefork:notice] [pid 8760] AH00163: Apache/2.4.18 (Ubuntu) configured – resuming normal operations
[Wed Apr 11 17:52:44.983343 2018] [core:notice] [pid 8760] AH00094: Command line: ‘/usr/sbin/apache2’
[Wed Apr 11 17:52:49.423408 2018] [core:alert] [pid 8763] [client 192.168.1.10:59150] /var/www/webcore/.htaccess: Invalid command ‘RewriteEngine’, perhaps misspelled or defined by a module not included in the server configuration
[Wed Apr 11 17:54:58.086854 2018] [mpm_prefork:notice] [pid 8760] AH00169: caught SIGTERM, shutting down
[Wed Apr 11 17:54:59.224280 2018] [mpm_prefork:notice] [pid 8823] AH00163: Apache/2.4.18 (Ubuntu) configured – resuming normal operations
[Wed Apr 11 17:54:59.224332 2018] [core:notice] [pid 8823] AH00094: Command line: ‘/usr/sbin/apache2’
[Wed Apr 11 17:55:03.962800 2018] [core:alert] [pid 8826] [client 192.168.1.10:59262] /var/www/webcore/.htaccess: Invalid command ‘RewriteEngine’, perhaps misspelled or defined by a module not included in the server configuration
Can you run this
sudo a2enmod rewrite
sudo service apache2 restart
Incredible! Thanks, came right up! For my knowledge, what was "a2enmod" If its too much to say, just let me know, I'm happy to google as well. 
It’s for the URL RewriteModule.
Webcore only has one real page, but you’ll see paths like ip/piston/pistonid or ip/settings in webcore.
The rewrite module will redirect all the paths back to the main page
Came up, saw my pistons, but when I click to edit, it’s just spinning. Getting close though
Is my install messed up? I was looking at it looks like I have two installs of the app. I cannot delete the extra one (not OATH), says its used by dashboard, and the other one is used by Hubutat. 100% not related to the web server stuff, just did not notice until now.
I
It seems like it. I don’t think any of the changes we made would have caused that. Is it possible you loaded the webcore app twice in the apps page at some point in time? You might be able to remove the extra dashboard ( the one without Dashboard on the right but has it in the title) and then try to remove the extra main app. I’d recommend making a backup before attempting that though.
That worked, thanks. Not sure how it happened, but its all good to go now, and super fast with local browser
I think this guide needs to be sticky’d in some way. Everyday I login, there is something new you have contributed to webCoRE on Hubitat! 
If you don’t mind, then I am hoping to link this in the opening post.
I myself run the code on my VPS (for out of home access) and find the responsiveness of the UI mostly similar. Are you guys seeing drastic improvements when running it locally?
Thank you so much for doing this work. It makes sense to have webcore locally. I am not seeing anywhere in the webcore settings on hubitat to enable custom urls or add the address of my pi. What am I missing?
It should be there when you access the webCoRE primary app from the Apps section in Hubitat, if you are running the latest code from the GitHub.
Screenshot from mobile device given below...
The idea of running the webCoRE dashboard locally sounds really appealing, but, honestly, it’s over my head. Could I get some context?
It seems from @jp0550’s introduction, you were motivated by a deficiency in handling large pistons. Is this the primary benefit and how likely is it that most of us will hit this problem?
Is this also a strategy to insulate HE webCoRE users from the possible loss of access to the webCoRE servers?
The third benefit I see is just plain better response from a local server vs. the internet. Valid?
I have to admit that I’ve been looking for an excuse to play with an RPi, although I expect it will be a real time-sink. This might be it.
Thanks @ptdalen.
Sorry I didn’t get back to you last night.
Finished off today and all is good.
Thank you so much for this. I love webCoRE and it makes me feel secure that I can now expand my automation with Hubitat without the fear of losing the ability to edit/delete/define pistons.
Thanks again to you and @ajayjohnm for your efforts and instructions to open it up to us mere mortals.
@Errand
Have you got this working.
Just doesn’t want to work for me.
EDIT: Got it working by saving everything on the hub.
Doing a reboot and it started to work.
I already have a Windows server running apache & php … would this work if I ran webCoRE out of a subdirectory? Or would that entail crazy amounts of path edits to adjust for (or just plain not work)?
eg, http://[address]/webcore
I haven’t looked too much in the dashboard code to see how hard this would to be to change. Could you spin up another instance of the server on a different port instead and put webcore in the root?
yeah probably so, it’s just that i’m, you know … lazy 
Asking is the first easiest thing to do, what you suggest is probably the next easiest, onward and upward, lol.
I must be using the incorrect version? I installed from this link but don’t have the custom hub options on that screen.
webCoRE/smartapps/ady624/webcore.src/ webcore.groovy
Download the Hubitat app
