This is happening when trying to open a business or a quote or an invoice. Almost every section I am trying to open I get this error. I have to refresh the browser each time.
Can you be more specific? This is not an error message. If it happens when you try to open a business, how are you then able to open sales quotes or invoices? Does refreshing the browser restore a normal display?
Is this server accessible over the Internet? If you can send me URL to lubos@manager.io then I can have a look. There is not much to work with if nobody else can reproduce this issue.