What Happened To This Coin?

Not an error, just a damaged coin. It was probably removed from a mount of some sort, you can see extra bits of metal and solder around the rim.

Thank You very much on nice welcome and answer!

In June 1913, Serbia and Greece formed a new alliance against Bulgaria. The Serbian Prime Minister Nikola Pasic told Greece it could have Thrace if Greece helped Serbia keep Bulgaria out of Serbian part of Macedonia and the Greek Prime Minister Eleftherios Venizelos agreed. Seeing this as a violation of the pre-war agreements, and discreetly encouraged by Germany and Austria-Hungary, Tsar Ferdinand declared war on Serbia and Greece and the Bulgarian army attacked on June 29. The Serbian and the Greek forces were initially on the retreat on the western border, but soon took the upper hand and forced Bulgaria to retreat. The fighting was very harsh, with many casualties, especially during the key Battle of Bregalnitsa. Soon Romania entered the war and attacked Bulgaria from the north. The Ottoman Empire saw this as an opportunity to regain the territories lost to the Bulgarian advancement and also attacked from the south-east.
The Second Balkan War was now lost for Bulgaria, which sued for peace. It was forced to relinquish most of Macedonia to Serbia and Greece, while the revived Ottomans retook Adrianople. Romania took southern Dobruja. The two Balkan wars had greatly destabilised Bulgaria, stopping its steady economic progress and costing 58,000 dead and over 100,000 wounded. However, the revanchist demand to recover the bulk of Macedonia remained powerful.[68]