ReSharper Error: "The output has reached the limit and was truncated. To view the full output use 'Show Stack Trace in a new window' action."

When running unit tests in ReSharper, if the output is too long, it gives this error:

The output has reached the limit and was truncated.
To view the full output use 'Show Stack Trace in a new window' action.

Update

ReSharper fixed this issue in 2016.2, see answer from @Alexander Pacha.

Solution 1:

It took a few minutes of hunting. Click on the icon in the task bar:

Solution 2:

Due to the reactions from this post, JetBrains fixed this 'feature' and now allows the user to configure this in the ReSharper settings: Tools > Unit Testing > Unit Test Output > Limit number of lines in output to xxx. This fix has been made available in ReSharper 2016.2.