Here are a couple of tips to try: 1) when creating a character from a compendium drag, first make sure that no identically named creature already exists in the campaign. If you had a malformed character, dragging in fresh from the compendium will only place an instance of that malformed character. The compendium won't overwrite a local character of the same name (to protect your homebrew or edits). 2) Try in a private browsing window. If this works, then delete cache and cookies and check browser extensions for anything that might be blocking data (ad blocker, VPN, virus filter, etc.) 3. When dragging in a fresh character from the compendium, wait a few seconds before selecting or opening the token, particularly on larger characters. Make sure the event has a chance to resolve. This can be longer on slower connections, slower computers, or if a cookie or extension is interfering.