File upload issues; error: object object

When attempting to upload files (PDF) to File Manager, I get the following: Error [object Object]
What might be causing this and how can it be fixed?
Thank you.

In the dashboard, enable full diagnostic output, and you should get a more detailed report.

Also check the log, there may already be a more detailed report.

Thank you JohntheFish.
Here is what comes up in the logs:

exceptions Emergency Exception Occurred: /home/w3vinocouver/public_html/site/concrete/vendor/league/flysystem/src/Adapter/Local.php:322 Class ‘finfo’ not found (0)

Any thoughts on what I do about this?
Thanks again.

It looks like your php configuration is missing the finfo component. See PHP: Fileinfo - Manual and in particular installing/configuring. You should discuss this with the support team at your web host.

Thank you for your help!
In c-panel, I needed to select fileinfo under php extensions.
Seems to be working… much appreciated!
Now drafting a separate question…