I have a number of assets resources all set to upload to the same amazon s3 bucket. Two of my four assets resources show "An unknown error occurred" twice when I view them in /admin/assets
.
The files in the folder do not show up. In the logs the following error appears:
Error: Call to a member function format() on null in /apps/cms/craft/app/helpers/AssetsHelper.php:81
When I click Upload files I can upload files, but they do not show up once the upload has finished (no files are shown). They do get uploaded to s3 though. The message "an unknown error occurred" appears again.
Subfolders in that same folder show up perfectly and have all of their content visible and it is possible to upload new images without a hitch.
How can I get the top level folders to work again? What could cause this?