EVE NG | failed to write configuration file

Couldn't find anything on Google about this so I thought i share:

I wasn't able to save or erase config on the IOL routers in EVE:

R1#wr
Building configuration...
% failed to write configuration file[OK]

R1#wr er
Erasing the nvram filesystem will remove all configuration files! Continue? [confirm]
% failed to write configuration file[OK]
Erase of nvram: complete

I exported the config and cloned the lab. Then I was able to save again. Thank you, colleague!