frontend upload issue

recently,

when i upload a photo on the frontend the screen freeze after the upload(green bar ok) i resfresh the page and see the photo uploaded

i also see an js error in the console :

Uncaught ReferenceError: wppaUploadButtonText is not defined
at Object.success (VM14439 wppa-all.js:4:19876)
at options.success (jquery.form.js?ver=4.3.0:282:18)