Definition contains invalid parameters
I was working on editing a past flow and on modifying it, I was receiving "Definition contains invalid parameters" error.
On researching the internet, only hints mentioned were that there might be some new fields added to the list after flow creation - This was not the case for my list.
Other probable reason could be that there might be a column where it is mentioned as mandatory inside the flow but its not populated with dynamic value.
Second reason provided me some clue for resolution but that was also not the issue because of which above error was happening in our scenario.
One field was multi valued,one was people picker, one was multi valued people picker, all were mandatory inside the list but in flow these were not marked as mandatory.
I was not able to select correct dynamic values for these fields but can select for other fields of the list inside the flow.(as you can see in above screenshot)
What I did to resolve it was to make these fields of the list as optional, Updated the flow and than again made these fields as mandatory inside the list.
Eureka Problem solved :) but I am still not able to know why it didn't happened at first place. (may be MS has changed something at back-end engine as they are making lot of innovations in office 365 technologies).
Thanks for reading