# In Evolution, how do I fix "Empty cache file" errors which confound filters?

In Evolution email, I'm getting these error messages in blue at the top of the window. There are various messages indicating failure of processes, such as:

Execution of filter 'Junk check' failed


They always have the "Empty cache file" bit. I have tried trashing the cache:

trash ~/.cache/evolution/mail


... which seems to force it to rebuild the cache, but the errors continue, and filters continue to fail. The most annoying effect is that spam is left in my inbox, and other messages that should be automatically filed have to be filed manually. What can I do to fix this?

\$ dnf list installed |grep -E 'bogo|evolution'
bogofilter.x86_64                     1.2.4-4.fc23                 @@commandline