'Next' button freezes after 3 documents.

[jaideepmurkute]

I have tested with the MLQA dataset files as well as my custom dataset. Tool can process any number of single/multiple paragraphs up to the third 'document'. Then freezes.
If I put all the context paragraphs in the same document i.e. under the same 'title' in the JSON file, it works fine.

So,
1] I cannot browse previously existing datasets as they are.
2] Cannot put context paragraphs under different titles in new datasets.

I've tested on chrome as well as edge browser.
Have installed the latest version from git.