When I create the snippet review and write a comment review, the description of review and reviewer appears in the right side of the snippet. But when I put the cursor at the reviewer, it does not retrieve the information of that reviewer. It shows an error message 'error Not %20Found'. I have attached the User_Not_Found_Error.png file for that. I did not find any exception in the fisheye log file. When I click on the reviewer link, I found an error message ' The requested resource cannot be found. NOT_FOUND. I have attached the screenshot Fetch_User_Exception and the fisheye log files. Attachment Log_Files contains all the log files and the screenshots.
I tried to reproduce this problem in a Crucible 2.7.15 instance and it worked for me. What's the version you're using?
Do you use any external user management tool such as Crowd, LDAP, etc? If yes, can you try to re-sync your users?
Do you have a proxy configured? If yes, could you please try to bypass your proxy settings to see if it works? This will help us narrowing down the problem.
I could not find the attachments you mentioned. If the problem continues, could you please raise a new Support issue at https://support.atlassian.com and attach those files?