Power Query : How to handle "DataSource.NotFound: File or Folder: We couldn't find the folder " error - powerbi

Question

I'm trying to get the folder contents using the query below and also handles the error. But still I'm getting the text with a warning icon - "DataSource.NotFound: File or Folder: We couldn't find the folder"
See the M-code below:
let
Source = Folder.Files("\\serverpath\Desktop\"),
AlternativeOutput=#table(type table [Name=text,Extension=text,Availability=text], {{"Error", "Error", "Folder not available"}}),
TestForError= try Source,
Output =
if TestForError[HasError] then AlternativeOutput
else Source
in
Output

Answer 1

This is likely a bug, which explains why try...otherwise also doesn't work. The HasError field is returning false even though we get a DataSource.NotFound error. I've filed an item on our end to track this issue.

Answer 2

You need to force evaluation of the Folder.Files at each try / otherwise attempt, using Table.Buffer
= try Table.Buffer(Folder.Files(path1)) otherwise Folder.Files(path2)
you can then evaluate multiple paths, such as the same onedrive account if used on different computers having different login credentials i.e named username on one pc, but user.name on another (e.g personal computer, work computer)
= let SourceA = try Folder.Files("C:\Users\Username\OneDrive\Documents\"),
SourceB = try Folder.Files("C:\Users\User.name\OneDrive\Documents\"),
DynamicSource = try Table.Buffer(SourceA[Value])
otherwise Table.Buffer(SourceB[Value])
in DynamicSource