[[MediaWiki:Simplebatchupload-max-files-alert/en]]
The message lacks indication of the quantity of files allowed (aside from the one being used for PLURAL), and should look like this: You cannot upload more than $1 {{PLURAL:$1|file|files}} at a time. Correct it, please.
Piramidion (talk)
Submitted a PR for this change here - https://github.com/ProfessionalWiki/SimpleBatchUpload/pull/34/files
Regards,