I thought I had the same problem, but for me it's a little different.
The original post is seeing 0 MB for the library size and missing objects. I have a project in v.22 and in my Library Manager I don't see any size, not even a "0", it's just empty. I also don't see any warnings about missing objects.
However, the placed objects are in fact missing and I also can not seem to be able to choose from the BIMcloud library when placing a new object.
We are 6 users in the same project and it's only me having this issue.
I have tried the suggested workaround from Noémi, I have deleted and added again the library, but it didn't do any difference for me.
From what I understand from this workaround, it had something to do with Local Data, so I thought I would delete them manually, but the problematic library is not even on the list in my Local Data Manager.
Is this issue project specific, or do you experience the same with other projects?
I would try to re-upload the library to BIMcloud first, if it solves the issue. If still no luck, I can imagine that you might have objects with long name or deep in a folder hierarchy, which might causes this thing to you. Worth a check in solo.
Last, but not least, contact your support (Nolliplan, I believe) and ask for their help.