"Parent folder does not allow files to be created"

[StuartRobertHarris]

I know there are a couple of conversations on this topic - I followed the suggestions in those threads, but to no avail.
I am running the latest (per 18th May 2020) version of Lightroom Classic on a new MacBook Pro 16" running the latest Mac OS.

I recently moved my LR catalogues from a 2015 MacBook 15"to an external drive G-Drive. They opened fine from the G-Drive on the 15" but they won't open on the 16". I have made the permissions Read and Write on the Volumes Info, I have added Lightroom CC to Full Disk Access in the Security and Privacy settings. 
What to do?

[dj_paige]

You need to check the permissions on the FOLDER where your Lightroom Catalog is located, and ensure that this FOLDER has write permission. The permissions on the volume/drive are not the proper permissions to check.

[StuartRobertHarris]

YES!! I followed your suggestion and LR has opened the LR catalog. Thank you.

However, all that shows in the Library view now is blank tiles. When I switch to Develop and click on the tile, I see the image.

Is there a way I can see all the images in Library without going into Develop and clicking on each tile?

Many thanks in advance

[dj_paige · Accepted solution]

The previews have not been built for the Library Module to display. If you select a single gray tile in the Library, and then Library->Previews->Build 1:1 previews and wait a few seconds, does the thumbnail appear?

[StuartRobertHarris]

I checked around for tips and did the following: quit LR, found the Previews folder and renamed it, then re-opened LR. The Library module is now generating Previews.

All good.

Many thanks for your prompt attention.