Fonts missing warning when .ai file is placed whitin an Illustrator file

Hi all,

We have an Illustrator document, inside this document another Illustrator document is placed as a link. The placed Illustrator document contains live text and does not show any missing font warning when openend. If we open the document with the linked file in it, we suddenly are confronted with the following warning.

The myriadPro-Regular is activated on the system and used in the 'main' file as well as the linked file. If we convert the text, in the linked file, to outline, the document opens without any warning, as soon as we type any text in the linked file, the error is there.

Any else having this issue, or even better, the solution for this, please let me know.

Tested in Illustrator CC 2015.3, 2018 and CS6 on a Mac computer with OSX 10.12.6 and OSX 10.13.1 with Universal type client as fontmanagement.

JJ