Tor relay crashes at consensus_diff_queue_diff_work() with assertion in_main_thread() failed

When I start a relay with latest Tor version, it almost instantly crashes:

Aug 02 11:04:45.000 [err] tor_assertion_failed_(): Bug: consdiffmgr.c:1601: consensus_diff_queue_diff_work: Assertion in_main_thread() failed; aborting. (on Tor 0.3.1.5-alpha )
Aug 02 11:04:45.000 [err] Bug: Assertion in_main_thread() failed in consensus_diff_queue_diff_work at consdiffmgr.c:1601. (Stack trace not available) (on Tor 0.3.1.5-alpha )

OS: Windows 7 SP1 x64 Tor: 0.3.1.5-alpha x64 (custom MSYS2 build)

Trac:
Username: Vort

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