Purchased Lifetime Account: But not Updating Plugin

Hi

I purchased the lifetime account for this app at least a year ago and now it says “There is a new version of ARI Stream Quiz available. View version 1.5.51 details or update now.” in my plugins (I am stuck with version 1.5.45) and when I try update it it says “Update Failed: The package could not be installed.” I can’t find any person to contact and no support to resolve this.