How can I fix the 'parameter missing or invalid' error after uninstalling a sales funnel app?

[rafiqhaider]

i recently installed an app for sales funnel, One Click Upsell - Zipify OCU. i created a funnel for upsells , i wasnt happy with it so i unpublished it and deleted the app , eversince every time a product is added to my cart or a checkout is completed i see a broken page with this error message parameter missing or invalid (Image Attached) . on all the pages where a pop up was working this error is now displayed . please help me fix it .

[ZipifyOCU-Tasha]

Hey there, 

Tasha here with Oneclickupsell. 

I just wanted to check in to see if you were able to get this issue resolved. 

I can look into your account to see if there was any leftover code causing a conflict if the issue is still present. 

Best,
Tasha