for can't access VM. I had that issue in the logs it said VM read only something to that effect. Had no access to VM or Messages whatsoever or record any messages.
I shut down the system pulled the SD card blew some air in the slot put the card back in restarted system and VM worked like it supposed to.

My theory is the space around the SD card air is pulled in by the cooling fan and over time dust gets in that area. I think the sensor that detects wether the SD card is locked or not is like and optical sensor if thats the case than some dust could cause the sensor to think the write protect tab is enabled thus killing the VM.

This is just a theory but doing this worked for me. I see the date of this post most likely you found a solution and it was something else would like to know how you fixed that issue so i can learn if it happens to me like it happened to you thank you