Error running some software and sound crackling problem

[alo0oz]

i have been using mint for a year now. before this time i was never bothered with such problems.
updating from 18.2 to 18.3 cinnamon caused high memory and cpu usage problem.
then i switched to manjaro for a month.
then i switched back to mint, this time installed xfce variant.
I though it was ok.
but for some time i'm having some problem.
sound is crackling and stuttering.
Some softwares are getting installing just fine but are not opening up.
megasync, time doctor, clementine etc are such applications.
when i try to access them via terminal, some symbol lookup error is thrown.
Please help me to solve these problems.
I don't want to reinstall os again.