From what it seems the webcam driver/software is not fully compatible with your system. In order to fix it, I suggest you uninstall it and download and install a compatible version from the official web page. In order to do this, press Windows + R key combination, type devmgmt.msc and expand the Imaging devices list. Right-click on the webcam driver, select Uninstall and reboot your computer. Next, using the Add or Remove Programs feature, uninstall the webcam software. After that, navigate to Acer Drivers and Manuals, identify your laptop model, select your operating system and download and install the provided files.