Why did Montenegro initially sign the Carrington Plan and then later change their vote?

Answer and explanation:

The President of the Presidency of the Republic of Montenegro, Momir Bulatović,  with the previously obtained consent and authority of the Parliament of the Republic of Montenegro to do so, accepted Carrington's peace plan, and the presidents of all member republics rejected that plan.

Under various, numerous and serious threats and coercion by Slobodan Milosevic and exponents of his regime, generals, loyal politicians, and media pressure, harassment and satanization of Momir Bulatovic's case in The Hague on October 18, 1991, Bulatovic's signature was soon withdrawn from the Hague Document. Lord Peter Carrington, Chairman of the Peace Conference on Yugoslavia.