Thanks for sending the files in. Here are a few things that might help.

These are primarily Arduino riles, the way it works unless I hear otherwise.

Arduino libraries are never #included with paths

Arduino libraries should always be #included with chevrons not quotes #include <myheader.h>

The .ino files must always be in a folder with the name name as one of the .ino files (not in the src folder (or below) which is for normal c++ files)

Visual Micro also expects the project name and project file name to be the same as the primary .ino and containing folder name. The project must be in the same folder as the .ino

In short I recommend using the Visual Micro menus to add your library includes for you, remove path qualifiers from library includes, move the .ino from \src into the project folder  and make sure the folder, .ino and project names match.

We might support .ino files in sub folders but I don't think the arduino ide does (or never used too) therefore we need to ensure compatibility

It sounds like the machine that works has different config. The licence key does not provide or restrict any functionality. It is not the issue. The \src folder functionality is a standard part of arduino and visual micro.

There is the vMicro>Compiler menu that contains an entry called "verbose" and an entry called "show build properties". Switching on these options and then building gives output which shows everything about your config and the build. Please switch them on on both machines, build on both then email the outputs as .txt files along with link to this thread.

Also zip and email the project folder from your other machine that works.

Thanks

You have switched on "show build properties" but haven't switched on verbose.

Thanks

There are some differences in the project files between the two machines.

Take a look at the ProjectDir= property

The old machine must have the project files in the src folder.

The old machine also has a local project board.txt file but it might be unused and is of no concern.

I guarantee you that the way you had your project setup was outside of the simple rules described earlier and should never have worked. Certainly never in Arduino IDE?

Can you confirm that the board.txt you have in the project folder of old machine is empty?