An error occurs when you try to vote for an article.

The console shows the following
Jquery.min.js: 4 GET www.sheruknitting.com/index.php?option=com_k2&view=item&task=vote&format=raw&user_rating=5&itemID=1097 500 ()
Send @ jquery.min.js: 4
Ajax @ jquery.min.js: 4
(Anonymous) @ k2.frontend.js: 178
Dispatch @ jquery.min.js: 3
R.handle @ jquery.min.js: 3

Screenshot from the screen in the attached file imgur.com/5KXzwMq
Please help, correct the problem.
Version K2 v2.7.1
Joomla! 3.7.4 Stable

A 500 error is a generic server-side error.
Please consult your error_log in order to see the actual error.

Here's the actual error:
1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 3

This is still a generic error, can you enable error reporting?

Has included displaying errors in Joomla and in PHP.ini Unfortunately, nothing is displayed. error.php file is also empty.

If you go to the site under the super user's profile, then everything works.
If you go under any other profile, it does not work.

Any user I give super admin rights and voting works fine.
I remove the user's right to super admin - an error. Just turn the arrow and that's it. No error messages.
Tell me, please, where to look for the error.

The error.php file is a template file.
You need to ask your hosting provider, where the error_log is located.
Furthermore which version of Joomla! and K2 are you using?
Any 3rd party K2 extensions?

I was referring to the file ERROR.PHP, which lies in the Joomla logs folder. Does not fix this error
I know where the provider has the server error file - it also does not fix this error.
Version K2 v2.7.1
Joomla! 3.7.4
Third-party extensions for K2 are not used.
PHP Version 7.0.17
Web Server Apache
WebServer to PHP Interface litespeed
PHP Built On Linux us9.default-host.net 3.10.0-614.10.2.lve1.4.56.el7.x86_64 #1 SMP Wed Jun 21 18:37:06 EDT 2017 x86_64
Database Version 5.7.16-10-log

I know where the provider has the server error file - it also does not fix this error.

It will not fix the error, but it will point to the actual error.

I know where the provider has the server error file - it also does not fix this error.

It will not fix the error, but it will point to the actual error.