Issue Collector error

[Susanne Sumskis]

Some users when 'submitting' the collector are not getting the 'wait 5 seconds' pop-up and their page is never resolving as completed.

There submissions are being received in the queue however they do not know due to lack of confirmation. 

Any guidance would be great. Here an error that was logged:

batch.js?locale=en-US:283 DEPRECATED JS - Dropdown constructor has been deprecated and will be removed in a future release. Use Dropdown2 instead.

Note: I am using the create collector in my instance so not sure how i would go about using 'dropdown2 instead'

Also a whole slew of errors today citing: [02/06/2020 19:59:34] Unknown error occurred trying to invoke collector

Thanks!