Seemingly random TokenMismatchException

hello I have an api I made using laravel. https://github.com/jung3o/VacStatus

I've had it running since a year ago and started off on laravel 4 and now on laravel 5.1 and I've always had this issue with TokenMismatchException coming up on my logs. In the last 14 hours my log had 26 TokenMismatchException errors reported. I always ignored it, but it's getting really annoying now.

I've never had this issue when I tested it around. All of my calls are using ajax and I use $.ajaxSetup({ headers: { 'X-CSRF-TOKEN': this._token } }); github (oh and this component is used with every class that uses ajax requests)

Is this an issue from my end? Is there a way to prevent this from happening even if it isn't something that is coming from me?

I remember testing api calls with some chrome plugin and I came across this issue with cookies being saved weird.