Can a Mistake in KVL Analysis Disprove a Fundamental Law?

[sandy.bridge]

Here's my work. When I apply KVL around loop 1, I get +5V, but when I apply it around loop 2, I get -5, which is inconsistent with my first results?

Where am I going wrong, or have I disproved a fundamental law?

 

[sandy.bridge]

Sorry, my work got cut out. The bottom says: +V+5=0, V=-5

 

[gneill]

I only see one loop. And what's the diode and resistor on the left supposed to be indicating?

 

[sandy.bridge]

I had redrawn the network on the left and configured it to the form on the right. This is how my textbook deals with KVL.

 

[sandy.bridge]

Never mind. I figured it out. I entirely forgot that there is a 10V drop across the diode.