Why doesn't category selection work in CMS DLE?

Question

DLE

When adding news, I go to the category field, a list box opens and instead of choosing when you click on a category, it is simply removed from the list. Thus, you can clear the entire list and nothing will be selected. The news is saved, but without a category. You can fix it manually (in the post table via phpMyAdmin ) and then everything works.
The categories themselves do not disappear from the list. Tried export-cleanup-import of the table. The cache was cleared with the "Clear Cache" button and deleting files from the cache directory.
DataLife Engine Version: 9.6
Operating System: Linux 4.4.0-133-generic
PHP Version: 5.2.17
MySQL Version: 5.6.25-73.1 MySQLi

Answer 1

Ideally update to the latest version and everything should get better, although it looks more like a js problem, this can be seen most likely through the developer tools (console)