Aporte original por: JAI GANESH NAIDU ,
Seems that the tapes are not been used for long time; this happens in unused cassettes as the tapes gets stick to one another. Hold the cassette in one hand and gentle tap it on your secondhand’s palm. Most of the time it should solve the issue. (This method needs to be done very carefully as there is a risk of tape getting damaged) In extreme cases you need to open the cassette and release the parts which are stuck together.