Windows 10: max path length - inconsistency

I came across a strange problem recently and so far I am not able to find a reason for this behavior

I have a very deep folder structure with two files. This folder is actually a Sharepoint Team Site synced with OneDrive fB


File 1 - synced from sharepoint:

"C:\Users\[my username]\[company]\[Folder1]\[Folder2]\[Folder3]\[Folder4]\[Folder5]\[Folder6]\[Folder7]\[Folder8]\file1.jpg"

in total, this path is 247 characters long. I can rename the file to whatever I like, as long as I do not get longer than 247.


File 2 which is actually a copy of file1 I made in Sharepoint - so it is synced from sharepoint:

"C:\Users\[my username]\[company]\[Folder1]\[Folder2]\[Folder3]\[Folder4]\[Folder5]\[Folder6]\[Folder7]\[Folder8]\file2_longname.jpg"

I can rename this to anything up to 259 characters in total - just as you would expect.


File 3 which is actually a copy of file1 I made in my local explorer:

"C:\Users\[my username]\[company]\[Folder1]\[Folder2]\[Folder3]\[Folder4]\[Folder5]\[Folder6]\[Folder7]\[Folder8]\file3_longname.jpg"

I can rename this to anything up to 259 characters in total - just as you would expect.


If I rename the file1 in sharepoint to any longer name, I can also rename the file in explorer to up to 259 characters. Until I shorten it down to the original 247 characters which I can not exceed anymore. If I go below 247, I can always return up to 247.


What is this behavior?

Why am I not able to rename file1. And how do normal users know where the limit is at, if it is - for some reason - below 259?



Update:

Just after posting this, I found another quite interesting point. The problem is not this one specific file!

If I create a new file in explorer, the path can get up to 247.

If I create a new file in sharepoint, the path can exceed 247.

If path > 247 && path < 259 then I can rename up to 259

if path <= 247 I can rename up to 247


So, I think I at least found the consistency in this, but I still miss the reason. I do not know about a path-limit of 247

:)

 

Open File dialog cannot open multiple files if some (but not all) of them have paths that exceed the max path length

More of a bug report than a question...

The native Open File dialog fails with the following error message when you try to open multiple files from the same folder and some (but not all) of them have paths that exceed the max path length.

"You can choose multiple items only if they are all located in the same folder."

I assume this happens because Windows will prefix the path with \\?\ if the path of a selected file is too long (see

https://docs.microsoft.com/en-us/windows/win32/fileio/naming-a-file#maximum-path-length-limitation). Now, if only some of the selected files have a path that is over the limit, only some of the files will have that prefix. No longer do all files have the
same parent path! Windows is apparently doing a rather simplistic check (like a string comparison) to see whether selected files are in the same directory.

 

Path length limit

Hello John,

My name is Patricia and I am an Independent Advisor. I am here to help you today.

Disable the path limit length is recommended after Python setup is successful, because if python was installed in a directory with a path length greater than 260 characters, adding it to the path could fail.

So don't worry about that action and proceed to it.

 

Path length limit

I want to install Python. Should I disable the path length limit? Are there any negatives to doing so?