Now in regard to your question to hide the error: that strongly depends on whether this dialog is rendered client-side or server-side. If it is rendered by Jira server-side, it will be difficult to fix this without making changes to the installed instance.
Keep in mind: if you’re going down this path you might experience a lot of unexpected behaviour and other errors. Without any doubt, the best solution would be for your client to adhere to the supported browsers list.
@muthukumaran.g Microsoft Edge should actually be supported, it was added in Jira 7.1.4. If you are having difficulties with Jira on Microsoft Edge, you should report this as a bug to Atlassian Support.