i woudl say that this is the expected behaviour and is why joomla itself will not allow you to create a folder with a space in it

yes, creating a new folder with a space in it you get the error message, but no error message when try to open it in the media manager.

AlexRed, Joomla use a safe pattern to remove any char that can give problems.
Space can break, so Joomla remove it.
test space, is changed to testspace (no space inside) it's why media manager cannot show inside this folder.

Maybe you can add a warning icon near the file/folder name, like some others media managers when a name is wrong or contains not accepted characters.

I wonder if we could not use rawurlencode() after domain to get the nice + or %20 for spaces, therefore permitting spaces in folders title.

It might work but it might be tricky if you have nested parts that all need encoding

This is not an issue in J4.

Since this issue arises when performed outside of Joomla, can this be considered as won't fix?

Set to "closed" on behalf of @alikon by The JTracker Application at issues.joomla.org/joomla-cms/18287

Is there a way to fix this in code or any patches available. I am having this issues in my site. How to fix this. I cannot traversing the folder with spaces. but i can go inside folder without spaces.

@rashgang
The simplest way is to change the names of the folders via FTP or CPanel.

If i changed it it will affect the image path on frontend.

Mass changes in a db dump.