Quote from: happy_merchant on August 10, 2017, 04:37:36 AM

Ah, you're right, that was around the same time.

It also happened again quite a bit later at block 604 with the same error as block 584/585:

Code:

2017-08-09 23:33:45 UpdateTip: new best=000015cb5f14b102bd89e9cd1c1e835e9ee56754895a7b6208272c40cac135fa height=604 log2_work=26.525747 tx=2109 date=2017-08-09 23:33:43 progress=0.002907 cache=0.4MiB(1967tx)
2017-08-09 23:33:45

** TestBlockValidity FAILED - pindexNew->pprev != chainActive.Tip() (assert(pindexNew->pprev == chainActive.Tip())); **

2017-08-09 23:33:45

BiblepayMiner -- runtime error: CreateNewBlock: TestBlockValidity failed: (code 0)
2017-08-09 23:33:45 ProcessNewBlock : ACCEPTED
2017-08-09 23:38:45 UpdateTip: new best=00001db3d3ff8196dc01a228037e4c88254b44aa730e222b7e256426e207cb25 height=605 log2_work=26.533668 tx=2110 date=2017-08-09 23:38:43 progress=0.002908 cache=0.4MiB(1968tx)
2017-08-09 23:38:45 ProcessNewBlock : ACCEPTED
2017-08-09 23:58:15 UpdateTip: new best=00001744716e7698fcaae5352b51c16dde765c7c7a26d1ecbd333790e62ca92b height=606 log2_work=26.542772 tx=2111 date=2017-08-09 23:58:13 progress=0.002910 cache=0.4MiB(1969tx)
2017-08-09 23:58:15 ProcessNewBlock : ACCEPTED

Went ahead and enabled debugmaster, will check in the morning to see if it happens again tonight.

Edit: seems like a normal fork or reorg. Were you watching the network to see if that happened?