I have created a custom master page and set it as system master page.when clicking on 'More' under 'People and groups'.
I have referred this link. all the tags are included in the custom master page. But No luck
Please suggest some idea to solve this issue.
more group. If thats work fine, it means there is some problem with the custom master page only. And if that is the case, try to get the exact error by the methods suggested by @Yayati