I ran into the same issue. Removing the caluclated column resolved the problem.

Is there any way to have a calculated column without breaking the smartobject methods? Here is the calculated column I used to show a hyperlink:

="<a href='fsite]"&Project_Code&"'>"&Project_Code&"</a>"

SP should not allow you to use a calculated column to inject HTML and that will not work with K2.
Based on the documentation for Calculated Column, there is no expectation that the HTML 'trick' ever intended by Microsoft. https://msdn.microsoft.com/en-us/library/office/bb862071(v=office.14).aspx

I had the exact same issue with adding a calculated column (for a percentage) and it broke my form.  Had to remove the column but this is not going to work long term, adding a basic mathematical calc column to a list is pretty standard functionality and should not completely break a K2 form.  Is there any fix for this coming?

Feel free to add a request to ideas.k2.com to place this on our Fixes list.