After upgrading to joomla 3.7.2, I get a "Oops! Try to close the page & re-open it properly" message when I select any item in form, field and list managers. Also I get a error 500 when clicking on the seblod links on the frontpage.
try to install Seblod over existing installation again, could be installation got mangled. Also try contacting your hosting provider what the real cause is, 500 indicates either there is something wrong with the server, but it can also be an error triggered by protection system like mod_Security.
The question was solved by connecting the MySQL module to the PHP. But now another problem: all the materials created through the Seblod forms issue a 404 error. All references are relative.
If your php was not compiled with mysql support it is possible antoher thing is missing e.g. mod_rewrite.