So I can understand the severity of this, do you see any negative effects other than the assertion failure?
If turning off the assertion removes the client stalling while it deals with the breakpad stuff, then I assume none but equally cant confirm that :)
Nothing extracted yet.
Opted into a public beta for Frozen Synapse, went to verify game cache and had an assertion failure. Left the beta but verification is still causing the assertion.
Verifying the game cache of other titles seems to be fine, though.