iconv() error when importing participants

[Narabear]

I was just trying to run an update import as I usually do, and keep getting the error show on these screen shots.  Not sure what is happening here- the import file is no differet than what I usually use.  Any advice much appreciated! 

Thanks

[joanne]

Although you suggest there have been no changes, if importing used to work and it doesn't now then something HAS changed, so you need to find out what.

Has there been a change to your hosting environment?
Have you upgraded civicrm?
Have you installed or updated a new module?
Have you changed any configuration in civicrm?
etc.

[Narabear]

I only meant that I was using the same import process/ file format as usual.

No, we haven't upgraded, added a module, or otherwise changed any configuration I can think of that might be creating this.   We must have done something that's causing it, but I have no idea what.  Off the top of my head, the only thing I have changed recently is adding some custom fields options to the registrants for this event.

Does anyone know what change/ issue might cause this specific type of error?  Could it be the field additions?

Thank you