From 19 July through 24 July, the Stacks testnet had experienced repeated outages every few hours. The symptom was the repeated recurrence of errors such as the following:
WARN [1595867918.213] [src/chainstate/stacks/db/blocks.rs:2861] [ThreadId(6)] Block 36a6b25fb7dd1775761b80b567425dd886f35272a5cc6a7661df0d99662f9d1c state root mismatch: expected 2fbb24799b4ea08ca50a8a2c75749735a6aa60415758a1394525f789a109067c, got 65fbf51eea07de1a75c5c45373c6aa3c7975e88269948114c0468acbf461cf66