Invalid link for change control approvals

Invalid link for change control approvals

Everyonce in a while when clicking on link to approve a change control by users get the following message.  Can anyone tell me what it means and what can be done to correct it.  Currently running 8.0.0 8008
 
 
 
Invalid Key : Key could have been changed manually or would have been an
old one. A mail with the updated key would have been sent to you

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