diff --git a/src/init.cpp b/src/init.cpp
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -2400,6 +2400,10 @@
                 pcoinsTip.reset();
                 pcoinsdbview.reset();
                 pcoinscatcher.reset();
+                // new CBlockTreeDB tries to delete the existing file, which
+                // fails if it's still open from the previous loop. Close it
+                // first:
+                pblocktree.reset();
                 pblocktree.reset(
                     new CBlockTreeDB(nBlockTreeDBCache, false, fReset));