Just wanted to chime in to say that adjusting maximum duration for captures is most definitely the solution.  I've come up against this a few times with our Unity and every time it points to this solution.

I just started a project and after digitizing from a few different source tapes I started to get the same lame error message and I had plenty of drive space, etc. Where is this maxmun duration for captures setting? I went into capture settings to investigate but did not see. I'm using Media Composer Adrenaline v2.7.7

The only thing that worked for me was to digitize the media as OMF Media instead of MXF media and the problem went away. Hooray!!! Hope that might help someone on this thing.

open your capture settings, there is a tab for .mxf media, that settings should be less than your total storage available, so if you have 2 hrs available, make sure that is less than 120 minutes...etc...and it is only for .mxf files, that is why .omf files work...but if you are like us, .mxf is a much better way of media management, causing the avid to automatically make new folders so you avoid the folder file count limitation that .omf has.

Hi Joe, just curious as what version of Unity you have and what type of clients?  MAC or PC clients?

 Unity 5.0 with 5 Media Composer Arenalines 2.8.3 now, 2.7.5 when problem occurred, and 2 Symphony Nitrii (plural of Nitris, hehe) 1.8.3, was 1.7.5