Error encountered fetching data

Lately we have been having some problems with users that are getting the message ‘error encountered fetching data’. We have 200 users using Inotes and only 3 are getting this message. What we have found is that if we remove any email that has chinese symbols in it, then the message will no longer popup. This can be a problem when some of that email is important. We have looked for a solution and could not find one. Please advise.