I can't figure out what triggered this, whether it was an software Update or something else, but I can no longer navigate to my files from any application. When I am in an application and I want to open a file in a sub-folder, I click/double click on the folder and nothing happens. If the file is a root folder like Home or documents then there are no issues.
What is important to note, I can access my files in Nautilus with no issues, so to be clear, this only occurs when I am navigating to files using an application. (Tried Libre Office, Shotwell (import), Clementine, Thunderbird (attachment), GRAMPS (media import) as an example. I have checked my permissions and everything is fine.
Question Update: I have made some progress since I originally asked the question. I took the advice in some of the comment to change my theme, which I did from OMG to Ambience and now I can navigate using the now visible Open button. While this goes some-way to resolving the issue I still cannot click/double click on a sub-folder to open it as I could before.
Below is a screen shot of my folder structure in Home/Documents and I am trying to click/double click on the folders I have created within.