Hi Zeeshan

Thanks for your post, it seems as if the configuration is different between the two environments. Can you try to remove the other start integration as only 1 start integration is supported.

Dear Steve,

Thank you for giving attention to this post.

We checked for other start integrations, however there is only one start integration with the list smartobjects. We even tried creating a new workflow with a new list smartobject of a different site collection but the iframe used to become un-responsive right at the step where it used to search for all site collections which has K2 app for SharePoint activated.

We also tried running the registration wizard via the App catalog but this too didn’t solved our problem.

How this was fixed -

We did an IIS reset of our servers and tried looking into the problem area again. Surprisingly the issue was no longer there. This is strange !

I am yet to reach a conclusion as how this happened and how this got fixed post IIS reset. 

As of now the solution is working normal.

Regards,
Zeeshan Nasim