In the file chooser dialog, after files are selected, click the [+] button rather than [Import] button, all the files will be added to the list without copying. Reasily reads them from the storage directly.
This is useful if you manage your epub files by yourself in your own storage folders.
Some Reasily Pro users have reported that Reasily asks them to upgrade again.
This usually happens on your second device.
It is possible that Google Play on your second device hasn't updated the purchase state yet, so you could try: Clear memory, reopen the Play store to let it refresh purchase state. You can also try rebooting the device. Make sure the internet connection is stable.
If you have multiple Google account, the app should be installed with the account paying for pro before. That is, the account should be selected in drawer menu of Google Play when installing Reasily. Otherwise, Google Play thinks Reasily is owned by another account and is not paid. You can check whether the correct account is associated to Reasily by clicking the "Donate" in the menu. You might have to uninstall and install Reasily again with the correct account if the current associated account is incorrect.
If it is still not working, please tell me. I can refund money or give you a redeem…