Visual Studio 2015 new files not being added to source control automatically

Folders called Release and their contents is automatically excluded from TFS (along with Debug and lots of file types). You can override this for particular folders by creating a .tfignore file, as detailed in the "Customize which files are ignored by version control" section of this link

Customize which files are ignored by version control

By default certain types of files (for example, .dll files) are ignored by version control. As a result:

When you add ignored files to folders that are mapped in a local workspace, they do not appear in the Pending Changes page in Team Explorer.

When you try to add ignored files using the Add to Source Control dialog box (for example by dragging them into Source Control Explorer), they automatically appear in the Excluded items tab.

You can configure which kinds of files are ignored by placing text file called .tfignore in the folder where you want rules to apply. The effects of the .tfignore file are recursive. However, you can create .tfignore files in sub-folders to override the effects of a .tfignore file in a parent folder.

.tfignore file rules

The following rules apply to a .tfignore file:

# begins a comment line

The * and ? wildcards are supported.

A filespec is recursive unless prefixed by the \ character.

! negates a filespec (files that match the pattern are not ignored)

.tfignore file example

Ignore .cpp files in the ProjA sub-folder and all its subfolders
ProjA*.cpp

Ignore .txt files in this folder
*.txt

Ignore .xml files in this folder and all its sub-folders
*.xml

Ignore all files in the Temp sub-folder
\Temp

Do not ignore .dll files in this folder nor in any of its sub-folders
!*.dll

We have the same issue because of a branch called 'Release'. But the issue is only at Visual Studio 2015 Update 3. Using Visual Studio 2015 Update 2, everything is ok. So Visual Studio Update 3 must have been changed its behaviour. It would be useful to return to its old behaviour.

We were also experiencing this issue but in our case it was because we had folders that ended in ".Lib". Figured it out from this SO question: Visual Studio 2015. Files not added to TFS