There are two samples from the Bechstein piano which include a click in the first release of Akoustik Piano (which also became part of Komplete 5). There are two archives attached to this article which contain the fixed samples. One archive is for the 16-bit library and one for the 24 bit library as the names of the archives indicate.
Please download the file that matches your library installation (16 bit or 24 bit), copy the two included files to the Samples > Bechstein > Samples directory within your Akoustik Piano Library folder and overwrite the existing files to eliminate the clicks.