I downloaded the last version of metronic 8.1.16 ( the html demo7 theme ).
The issue is about the datatable's plugin (server-side processing) where the html div that contains the loading spinner and text, is displayed shifted to the left, and doesn't contain any message text.
I solved also this question....
The problem was that css file of datatable was not-linked.
Glad to hear that! Yes, since the datatable is a huge plugin it should be loaded on demand by referring to the documentation.
If you need any further clarifications please do let us know.