Ever since Microsoft released its anniversary update to Windows 10, they introduced a new feature which enables file names and paths longer than 260 characters. However, in doing this, they introduced a bug that is causing a lot of problems.
If you had Windows 10 and are connected to a file server or even a network attached storage device and you had file paths that were longer than 260 characters, for the most part Windows would not complain. It would allow you to modify, save, create etc. files with no problems.
After the Windows 10 anniversary update which included the new feature to allow file paths and names longer than 260 characters this broke everything. You see, you can able this feature through group policy and the only things that support or will allow you to use this new feature is a very limited group of applications. The application has to specifically be told to use this feature so everyone including Microsoft has to update their programs to utilize this feature. Windows Explorer in its current form does not support file paths and names longer than 260 characters. Whatever they did to include the new code which allows file paths and names longer than 260 characters is what is causing this bug to happen.
Symptoms of the bug is when you view a file or folder within Windows Explorer that has a file path longer than 260 characters Windows Explorer will close. Your desktop may also flash black momentarily and then come back with just your desktop showing. Another symptom of this bug is when you have a folder or file that is longer than 260 characters that is in your quick access area which is the default folder/area that Windows Explorer opens up to you will see a blinking Windows Explorer window non stop. I’ve also hard of people being unable to drag Windows Explorer windows across their desktop.
There are two workarounds for this as it stands but they’re simply that, workarounds, these are not permanent fixes because it gimps Windows Explorer.
The first is to go to View, Options, Change Folder and Search Options, click on the View tab, CHECK off Always show icons, never thumbnails.
The second is to change the way Windows Explorer opens up to quick access: Again View, Options, Change Folder and Search Options, on the General tab at the very top it says “Open File Explorer to and there is a drop down box with “Quick access” already select. Change it to This PC. and hit apply and then OK.
You can follow this thread: https://answers.microsoft.com/en-us/windows/forum/windows_10-files/long-file-paths-crash-file-explorer-when-accessing/82ef7806-41f0-4841-94a1-0010cb02bd69?page=2&msgId=31967051-23c1-405f-a42b-fb531d94be62 where there are multiple people confirming this bug.