Hi dot,
you can continue to read as usual, the CAN card/driver is not at a dead end. However, given that frames are lost any counting synchronization is now off, so depends on the type of application whether you need to restart your application or not. Also there might be circumstances where you want to discard everything in your buffers if you encounter one of the above mentioned errors. In those cases you could either flush the buffers (read all, but discard) or stop and restart the ports.
-B2k