FileBrowser will show a popup error when you tap on a folder and your user account doesn't have access rights to the content.
Here are some suggestions.
If you have connected as a Guest or user with no account, you may only have rights to see a limited number of folders or files. Using a named account should give you more access.
The Administrator account should have access to all available folders. You will need to enable this account and to give it a password. See the link below for more information.
To access the folder security controls, right-click a folder and choose 'Properties'. Then select the 'Security' tab.
If you don't see this tab it could be that 'Simple File Sharing' is enabled. See the link below for instructions on how to disable it.
The 'Security' settings tab allows you to control which users have access to shared files and folders. Common options are 'Full Control' (users may read, change and delete files) and 'Read' to limit access so files cannot be changed or removed.
If you need to reset the permissions of all files and folders within your shared folder, you can click the 'Advanced' button to find this option:
Selecting this option and clicking OK will reset all permissions to those you set in the table.