Hi AL and Damyon,
Apparently, I solved the problem by removing all the lines in my csv that didn't have an ID number linked to it. Somehow that's where it goes wrong, because since solving this, I've been able to upload competency frameworks without a hitch.
The plugin could however do with a more suitable error page when the imported csv file ends up not being valid because of such things. An HTTP 500, Bad Gateway or connection timed out page from the browser does not tell the developer where to correct the file.
For people constructing these frameworks, it's very tempting to have these 'comment' lines in the document while building, in order to know how it is structured.