Plugin SVN tag does not exist

Hello,

Plugin link

Getting this error.
The?Stable Tag?field is invalid, the specified SVN tag?/tags/2.7.8/?does not exist.?/trunk/?will be used instead.
https://i.imgur.com/Ol01TID.png

Tag does exist, see here

Could anyone tell, what’s wrong?

Thanks!

The page I need help with: [log in to see the link]