Just like the questions states, is there a hard limit to either the number of files or characters that can go in a file input in Internet Explorer?
Here's the test code:
<html><input id="files" type="file" name="files[]" webkitdirectory directory multiple></html>
I've been able to reach a point where files are not accepted with 4,680 files, each 6 characters each for a total of 28,080 characters. Each file is 0 KB in size as well. Additionally, this is being tested on windows with the test directory being C:\tempFolder.