ImageResizer and S3Reader2: The string was not recognized as a valid DateTime

I'm upgrading a website to a .NET website using MVC5 using ImageResizer with the images stored on AWS S3. The images stored on S3 are fine, have public read access and load without a problem when calling the S3 URL.

When I use the ImageResizer plugin S3Reader2 I get the following error on most of my images: "The string was not recognized as a valid DateTime. There is an unknown word starting at index 26."

You can find the ImageResizer Diagnostics here: Diagnostics

You can find the stack trace here: Stacktrace

Any help would be highly appreciated!