Software won't update because "my device is modified". How do I unmodify?

[AC Question]

I've tried everything under the sun, I've been through every end of Google and I can't figure it out. I've tried wiping it completel,, entering safe mode (all it days is downloading and doesn't go any further) I've tried clearing the cache, etc
Basically my phone was rooted but then I unrooted i,, but the files are still "custom" and "modified". Is there any way I can fix this?
I have the S4, I don't know what other information is needed
Thank you!!

 

[Bosbouer]

Flash the latest region/country specific OS from SamMobile for your s4 using Odin. See guide links below

http://forums.androidcentral.com/am...w-flash-stock-rom-via-odin-new-interface.html

[GUIDE] Unroot/Unbrick, Flash official stock… | Samsung Galaxy S 4 i9500, i9505, i9505G, i9506