I'm running ELOG on a windows server 2016. Just installed the windows installer and worked out of the box. 

Have you checked the firewall?

Hello, the following URL

https://foo.bar/elog/Shift+Reports/?new_user_name=a2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.com&new_full_name=a2seferewd%40fanneat.com&new_user_email=a2seferewd%40fanneat.com&newpwd=asdf&newpwd2=asdf&cmd=Save

causes elog 3.1.4 to crash. I attach full GDB trace

(gdb) set height 0
(gdb) set print elements 0
(gdb) set print frame-arguments all
(gdb) thread apply all backtrace

Thread 1 (Thread 0x7fc6d1624840 (LWP 1126)):
#0  0x00007fc6d06c6387 in raise () from /lib64/libc.so.6
#1  0x00007fc6d06c7a78 in abort () from /lib64/libc.so.6
#2  0x00007fc6d0708f67 in __libc_message () from /lib64/libc.so.6
#3  0x00007fc6d07a87a7 in __fortify_fail () from /lib64/libc.so.6
#4  0x00007fc6d07a6922 in __chk_fail () from /lib64/libc.so.6
#5  0x00007fc6d07a5e2b in _IO_str_chk_overflow () from /lib64/libc.so.6
#6  0x00007fc6d070d031 in __GI__IO_default_xsputn () from /lib64/libc.so.6
#7  0x00007fc6d06dd033 in vfprintf () from /lib64/libc.so.6
#8  0x00007fc6d07a5eb8 in __vsprintf_chk () from /lib64/libc.so.6
#9  0x00007fc6d07a5e0d in __sprintf_chk () from /lib64/libc.so.6
#10 0x0000000000423b5b in sprintf (__fmt=<optimized out>, __s=<optimized out>) at /usr/include/bits/stdio2.h:33
#11 get_user_line (lbs=<optimized out>, lbs@entry=0x2833748, 
    user=user@entry=0x7fffc84d0780 "a2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.combasar", password=password@entry=0x0, full_name=full_name@entry=0x0, email=email@entry=0x0, email_notify=email_notify@entry=0x0, 
    last_logout=last_logout@entry=0x0, inactive=inactive@entry=0x0) at src/elogd.c:25739
#12 0x0000000000433d0a in save_user_config (lbs=lbs@entry=0x2833748, 
    user=0x7704fc <_value+1500> "a2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.coma2seferewd@fonomsdfef.com", new_user=new_user@entry=1) at src/elogd.c:13343
#13 0x0000000000456068 in do_self_register (lbs=0x2833748, command=0x7fffc84d2650 "Save") at src/elogd.c:26768
#14 0x000000000045c1f7 in interprete (lbook=lbook@entry=0x7fffc84f92f0 "Shift Reports", path=path@entry=0x7fffc84d4430 "") at src/elogd.c:27594
#15 0x000000000045ecc6 in decode_get (logbook=logbook@entry=0x7fffc84f92f0 "Shift Reports", string=<optimized out>) at src/elogd.c:28393
#16 0x0000000000460970 in process_http_request (request=<optimized out>, 
    request@entry=0x284bee8 "GET /Shift+Reports/?new_user_name=a2seferewd%402sefddsfgfd.coma2seferewd%402sefddsfgfd.coma2seferewd%402sefddsfgfd.coma2seferewd%402sefddsfgfd.coma2seferewd%402sefddsfgfd.coma2seferewd%402sefddsfgfd.coma2seferewd%402sefddsfgfd.coma2seferewd%402sefddsfgfd.coma2seferewd%402sefddsfgfd.coma2seferewd%402sefddsfgfd.coma2seferewd%402sefddsfgfd.coma2seferewd%402sefddsfgfd.coma2seferewd%402sefddsfgfd.coma2seferewd%402sefddsfgfd.coma2seferewd%402sefddsfgfd.coma2seferewd%402sefddsfgfd.coma2seferewd%402sefddsfgfd.coma2seferewd%402sefddsfgfd.coma2seferewd%402sefddsfgfd.coma2seferewd%402sefddsfgfd.coma2seferewd%402sefddsfgfd.coma2seferewd%402sefddsfgfd.com&new_full_name=a2seferewd%40fanneat.com&new_user_email=a2seferewd%40fanneat.com&newpwd=asdf&newpwd2=asdf&cmd=Save", i_conn=i_conn@entry=1) at src/elogd.c:29201
#17 0x00000000004623d2 in server_loop () at src/elogd.c:30212
#18 0x0000000000404209 in main (argc=8, argv=0x7fffc84fb6c8) at src/elogd.c:3123

I added a user name validation in the current version.

Stefan

I wanted to change some CKeditor settings so tried modifying elog/scripts/ckeditor to no avail.

I wiped elog/scripts/ and dropped a fresh download of CKeditor4, with only the basic extensions. But when I open the elog it still shows the full toolbar, with elog default style and with all extensions operational.

If I leave elog/scripts empty, I get "CKeditor NOT detected" when starting elogd and the HTML option is empty and shows nothing, all as expected.

Does anyone understand this? Is there some CKeditor configuration file elog is defering to that I've overlooked? I have tried system wide seaches just in case.

elogd checks for the "scripts/ckeditor/ckeditor.js" file to detect the presence of CKeditor.

So it was just a clearing cache issue. elogd was telling the browser to use/not use CKeditor based on the aformentioned, and browser was then using the cached version. Fixed now.

And FYI for anyone who reads this when trying to modify CKeditor themselves, it seems elog needs the iFrame Editing Area plugin included.

It means that you could replace the currently distributed CKeditor with a fresh vanilla installation of CKeditor? 

Yes replacing the CKeditor folder with a vanila download works without issue, provided you clean the cache.
For what I originally wanted to do (modifiying the toolbar) I could have just run elog/scripts/ckeditor/samples/toolbarconfigurator/index.html and edited the config file, but a clean cache is needed (on Chrome, Firefox and Edge).