Worth mentioning that remove and open return bool - you're ignoring the return codes for both... Are they working?
Thanks, I wasn't checking those values at first but I added some code just now, both methods return true.
I've got no idea why your current approach wouldn't work - however to get it done, I think you should make some new code that, on update,
In the mean time, it's probably also a good idea to submit a bug report on the caching issue.
By timestamp based you mean name the file according to the current time?
Yes, something like this;