Warning Triangle Red in file label

Opening my most recent model, I find recently added and saved components - whole tags - have disappeared. On the model label in the list in Trimble Connect, used for opening the model into SU, there is a red warning triangle (with an exclamation mark in the triangle) with no narrative to explain what it means or what to do about it. And, similarly no narrative when I open the model. Significance and what to do, please?

These references should be bookmarked:

Hi again, Dan :
And thanks.
Does this mean I should have bought the Trimble connect app to save to / access from Connect?
I have models saved on Connect but I seem to be losing inputted drawing data between sessions - a synching problem evinced by the warning triangle.
You also mentioned before that it’s possible in Connect, to retrieve previous versions . . . Where would I learn this stuff?

I myself do not use TC, but I do not think so. I think your subscription to Go (or Mobile) would include TC usage.

I think that was Dave who said this. I think that this “file history” is a relatively new feature of TC.

From the TC User Guides firstly. Also, perhaps from product announcements.
Regarding the latter, Trimble Connect has its own product forum separate from the SketchUp forums.

EDIT: Actually, there is a dedicated TC category here in these forums (Aaron has reassign the topic):

I don’t know how new. I have files saved to Trimble Connect that have versions going back several years. The first one I looked at has V1 dated July 14, 2020 and a total of 17 versions saved in History.

Well, this shows then that I’ve only recently learned of it. The “age” of the feature was an incorrect assumption on my part.