I don't understand, it's just happen randomly in time,
I do nothing, just turned on plugin, but after time I'm checking and plugin turned off

I found this discussion https://elgg.org/discussion/view/1128943/plugin-auto-deactivation-problem but there is old Elgg version (1.8), and also no solution

If a plugin disables itself immediatelly after you enable it, the reason is most likely some unresolved dependency or conflict of the plugin (i.e. it either can't be used with another plugin you currently use or it requires some other plugin or a specific version of a plugin or a specific version of Elgg). In this case you should get an error message displayed at the top of the plugin page and you would also see the plugin's dependencies in the popup that opens when clicking on the plugin name.

If a plugin disables itself at a later time on its own it's very likely not a problem of the plugin or Elgg but rather related to the server configuration. It could be that SELinux is used on the server or the open_basedir php variable is used to protect control access to files and directories on the server. Why this would only happen at a later time I can't tell. The result would be that the files and folders would not be "visible" to Elgg anymore even if present.

I have no experience with either of these two. With open_basedir you would set the "allowed" folders in php.ini of the server (and if this variable is not commented out it's probably used). With SELinux I don't know how you would change the config if it's causing the problem. On a shell you could do a "ls -lZ" to figure out if SELinux is used (if there something else than a ? after the owner and group columns it probably is). Either way, it might be best to ask the support of your webhoster if SELinux or open_basedir is used and to ask them for help it this is the case.

Administration, please close this topic, it was my issue with the "mandatory" rules.

Thank you.