How to fix - “The solution cannot be imported - Some dependencies are missing” issue while importing solution?

Issue:

Recently we were moving a solution from one environment to other environment, and we faced the below mentioned error:

The following solution cannot be imported: [Solution Name]. Some dependencies are missing.

Analysis:

When we check the log, it gave us Json output of missing dependencies list. But we were not clear what to do with this. I tried to search the issue in google. But I was not able to find any exact solution for this.

Solution:

Our solution contains flows which were initially developed independently and were not part of the solution. So, the connections used in the flow were user connections and they were not added in solution.

So, I thought adding direct connections will fix the issue. But then I search what would be the ideal solution for this. I found out that we need to first create connection reference in the solution and then replace the connection used in the flow with the connection reference that we have created. The solution is using connection reference instead of connections directly. This took some time but eventually we got rid of all the missing dependency errors.