@faisalkhan Is fop2 completely broken now? Or is it that fop2 stops working over time? Basically, if you refresh the page, does it work again?
As far as getting a hint as to what maybe going wrong, you can see if any errors are showing in the Javascript Console in the web browser. You can also pull the logs from /var/log/asterisk/freepbx.log to see if anything odd stands out. Fop2 may also have its own set of log files, but I’m unaware of where those may live.