Hi Ramesh,
We couldn't able to reproduce the issue as you mentioned. It is working fine when the Prograssbar is placed inside MasterPage. Here are my suggestion regarding this issue.
* For each and every control Client side ID will differs when a control is placed inside other container(i.e MasterPage in your scenario). When the Progressbar is placed inside the MasterPage then Client Id for ProgressBar1 will preceded by ___sfctl00_ContentPlaceHolder1_ instead of normal __sfProgressBar1 Client Id. So You have to change it accordingly while invoking callbacks.This might cause this issue. So could you make sure this is taken care in your sample.
However we have attached one sample for your references.
ProgessbarInsideMasterPage.zipPlease have a look at our sample and do let us know if you need more help.
Thanks for using Syncfusion products.
Regards,
Gokulkumar.B