IMacros for Firefox Failure Corde 0x80500001 (Error code: -1001)

Solution

The root issue is the encoding of the files. I've had this problem before with iMarcos, but it's never been quite this specific. Usually saving the datasource (the CSV file) as UTF-8 works. But some update to Firefox or iMacros has made it really inflexible. Both the datasource (.csv) AND the macro file (.iim) file must be saved as "UTF-8 with BOM". I Used Sublime Text to do this, but any full-featured word editor should work.

For the record, various versions of things I use.
Firefox : 29.0.1
iMacros : 8.8.2
Windows : 8.1 x64

Problem/Full Story

I often have to fill out web forms over and over again to perform certain tasks. A lot of these web forms are poorly designed at best, and don't support batch-type inputs. So having a program like iMacros is essential for me not wanting to kill myself while filling out a DHCP registration form 200 times.

I've used iMacros for a number of years and never had too many problems; In Firefox at least, in Chrome the sandboxing makes it an exercise in keyboard snapping frustration to read/write to files -- but that's another story. However I needed to do a bunch of the previously mentioned DHCP registrations today (this is a system managed by another department, and the web interface is the only way to do it besides submitting a work request, which can take days), and found that the Macro/CSV I had previously used to do this were not working. I received the following error message:

Error: Component returned failure code: 0x80500001 [nsIConverterInputStream.init], line 4 (Error code: -1001)

I'd actually run into this error before, or at least one similar to it. iMacros (or possibly firefox), can be rather picky about the encoding it uses. Previously saving the .csv I use for inputs as UTF-8 had solved the problem. Today that didn't work though.

After fiddling around with it for a bit, I found something strange. I Created a new macro (.iim) file to see if the other one was corrupt or something, but writing/saving it through Sublime Text (not the built in iMacros editor) as UTF-8, then opening it in the iMacros editor just showed a blank file. Strange, after trying a handful of different encodings for the macro file I found one that it would recognize "UTF-8 with BOM". After saving the file with this encoding through sublime, it would show up correctly in iMacros. However, I was still getting the same error when I tried to run it. Tried saving the csv file with the same "UTF-8 with BOM" encoding, and then it ran.