it seems i get stuck at the exact same block every time i try to resync (even with older backups), its 26685.
the debug log displays the following in that case:
2017-03-24 09:06:07 received block b1d0f85c0c59a4ae3b4b85a23ed98e112119b4aec8de288e532d0b93fd157543
2017-03-24 09:06:07 ERROR: CTransaction::CheckTransaction() : Error: Node does not have mint zerocoin to verify, please wait until
2017-03-24 09:06:07 ERROR: CheckBlock() : CheckTransaction failed
2017-03-24 09:06:07 ERROR: ProcessBlock() : CheckBlock FAILED
2017-03-24 09:06:08 received block 1bdc95e25bfb1d0dc034149190b5faaae04447b6216c7a0c5fd6f894020b3a11
2017-03-24 09:06:08 ERROR: CTransaction::CheckTransaction() : Error: Node does not have mint zerocoin to verify, please wait until
2017-03-24 09:06:08 ERROR: CheckBlock() : CheckTransaction failed
2017-03-24 09:06:08 ERROR: ProcessBlock() : CheckBlock FAILED
2017-03-24 09:06:08 mempool.countZCSpend = 0
2017-03-24 09:06:08 CreateNewBlock(): total size 2503
2017-03-24 09:07:09 accepted connection 37.115.213.131:53678
2017-03-24 09:07:09 disconnecting node 37.115.213.131:53678
2017-03-24 09:08:07 received block b1d0f85c0c59a4ae3b4b85a23ed98e112119b4aec8de288e532d0b93fd157543
2017-03-24 09:08:07 ERROR: CTransaction::CheckTransaction() : Error: Node does not have mint zerocoin to verify, please wait until
2017-03-24 09:08:07 ERROR: CheckBlock() : CheckTransaction failed
2017-03-24 09:08:07 ERROR: ProcessBlock() : CheckBlock FAILED
2017-03-24 09:08:08 received block 1bdc95e25bfb1d0dc034149190b5faaae04447b6216c7a0c5fd6f894020b3a11
2017-03-24 09:08:08 ERROR: CTransaction::CheckTransaction() : Error: Node does not have mint zerocoin to verify, please wait until
2017-03-24 09:08:08 ERROR: CheckBlock() : CheckTransaction failed
2017-03-24 09:08:08 ERROR: ProcessBlock() : CheckBlock FAILED
2017-03-24 09:08:23 received block 83068ddd1f6f59a7bc3d2e1d0455886988b2bba02711c7f0d6574c4a2b716fa9
2017-03-24 09:08:23 ProcessBlock: ORPHAN BLOCK, prev=1ff911ec185e8f1f8611935f8cb10cf86155848b16f20c0cd039d8f760c0694e
2017-03-24 09:08:36 Flushed 1005 addresses to peers.dat 47ms
2017-03-24 09:09:05 received block fd0bbbad2cc5e1dbd91eb1351e1ba0f333a33c06b658404f268b47e30001955f
2017-03-24 09:09:05 ProcessBlock: ORPHAN BLOCK, prev=83068ddd1f6f59a7bc3d2e1d0455886988b2bba02711c7f0d6574c4a2b716fa9
2017-03-24 09:09:18 received block fd21e75c61cb9476b06843cf02e771b0e92ca0765455317a1070cc814eac900a
2017-03-24 09:09:18 ProcessBlock: ORPHAN BLOCK, prev=fd0bbbad2cc5e1dbd91eb1351e1ba0f333a33c06b658404f268b47e30001955f
2017-03-24 09:10:08 RandAddSeed() 204464 bytes
2017-03-24 09:10:08 received block b1d0f85c0c59a4ae3b4b85a23ed98e112119b4aec8de288e532d0b93fd157543
2017-03-24 09:10:08 ERROR: CTransaction::CheckTransaction() : Error: Node does not have mint zerocoin to verify, please wait until
2017-03-24 09:10:08 ERROR: CheckBlock() : CheckTransaction failed
2017-03-24 09:10:08 ERROR: ProcessBlock() : CheckBlock FAILED
2017-03-24 09:10:08 received block 1bdc95e25bfb1d0dc034149190b5faaae04447b6216c7a0c5fd6f894020b3a11
2017-03-24 09:10:08 ERROR: CTransaction::CheckTransaction() : Error: Node does not have mint zerocoin to verify, please wait until
2017-03-24 09:10:08 ERROR: CheckBlock() : CheckTransaction failed
2017-03-24 09:10:08 ERROR: ProcessBlock() : CheckBlock FAILED
2017-03-24 09:12:08 received block b1d0f85c0c59a4ae3b4b85a23ed98e112119b4aec8de288e532d0b93fd157543
2017-03-24 09:12:08 ERROR: CTransaction::CheckTransaction() : Error: Node does not have mint zerocoin to verify, please wait until
2017-03-24 09:12:08 ERROR: CheckBlock() : CheckTransaction failed
2017-03-24 09:12:08 ERROR: ProcessBlock() : CheckBlock FAILED
2017-03-24 09:12:09 received block 1bdc95e25bfb1d0dc034149190b5faaae04447b6216c7a0c5fd6f894020b3a11
2017-03-24 09:12:09 ERROR: CTransaction::CheckTransaction() : Error: Node does not have mint zerocoin to verify, please wait until
2017-03-24 09:12:09 ERROR: CheckBlock() : CheckTransaction failed
2017-03-24 09:12:09 ERROR: ProcessBlock() : CheckBlock FAILED
2017-03-24 09:12:42 accepted connection 95.32.250.73:57221
2017-03-24 09:12:42 send version message: version 99010, blocks=26685, us=130.83.137.28:29100, them=95.32.250.73:57221, peer=95.32.250.73:57221
2017-03-24 09:12:42 Added time data, samples 21, offset +2 (+0 minutes)
2017-03-24 09:12:42 nTimeOffset = +1 (+0 minutes)
2017-03-24 09:12:42 receive version message:Satoshi:3.0.0.9/: version 99008, blocks=27122, us=130.83.137.28:29100, them=77.45.241.121:29100, peer=95.32.250.73:57221
2017-03-24 09:12:51 received block 7b0d5d0b81335d2aca9468ca7e2248c9a85f0c52df8720d9c831fceb2898b994
2017-03-24 09:12:51 ProcessBlock: ORPHAN BLOCK, prev=fd21e75c61cb9476b06843cf02e771b0e92ca0765455317a1070cc814eac900a
2017-03-24 09:13:07 AcceptToMemoryPool: 149.202.137.169:29100Satoshi:3.0.0.8/ : accepted 82d07638e7a44801e5104c27f07021fa4e8858ac5f843771b09730b462a81836 (poolsz 7)
2017-03-24 09:13:07 stored orphan tx b8f07e97f6a398e2e113de563bde4327de3e39a7266819c918f31d9426db3a1b (mapsz 7)
2017-03-24 09:13:08 mempool.countZCSpend = 0
2017-03-24 09:13:08 CreateNewBlock(): total size 2729
2017-03-24 09:14:07 received block b1d0f85c0c59a4ae3b4b85a23ed98e112119b4aec8de288e532d0b93fd157543
2017-03-24 09:14:07 ERROR: CTransaction::CheckTransaction() : Error: Node does not have mint zerocoin to verify, please wait until
2017-03-24 09:14:07 ERROR: CheckBlock() : CheckTransaction failed
2017-03-24 09:14:07 ERROR: ProcessBlock() : CheckBlock FAILED
2017-03-24 09:14:08 received block 1bdc95e25bfb1d0dc034149190b5faaae04447b6216c7a0c5fd6f894020b3a11
2017-03-24 09:14:08 ERROR: CTransaction::CheckTransaction() : Error: Node does not have mint zerocoin to verify, please wait until
2017-03-24 09:14:08 ERROR: CheckBlock() : CheckTransaction failed
2017-03-24 09:14:08 ERROR: ProcessBlock() : CheckBlock FAILED
2017-03-24 09:14:39 received getdata for: tx 82d07638e7a44801e5104c27f07021fa4e8858ac5f843771b09730b462a81836
2017-03-24 09:17:04 received block 43aa6b7791ae5ae638bea7834ad1a3dff452c5b5b3abdae381f2deb5e30e652c
2017-03-24 09:17:04 ProcessBlock: ORPHAN BLOCK, prev=7b0d5d0b81335d2aca9468ca7e2248c9a85f0c52df8720d9c831fceb2898b994
2017-03-24 09:17:16 received block 2a1e29bcda24c83db9e6ac2d654ad889d562feeca173fa45dc847984d996cc77
2017-03-24 09:17:16 ProcessBlock: ORPHAN BLOCK, prev=43aa6b7791ae5ae638bea7834ad1a3dff452c5b5b3abdae381f2deb5e30e652c
2017-03-24 09:18:08 AcceptToMemoryPool: 178.57.58.128:54066Satoshi:3.0.0.9/ : accepted 96b1bdd548afe5f3abe73f2b68fe085aa959bd8cb4969c7b1068093e80846d67 (poolsz 8)
2017-03-24 09:18:09 mempool.countZCSpend = 0
2017-03-24 09:18:09 CreateNewBlock(): total size 2955
2017-03-24 09:18:28 received getdata for: tx 96b1bdd548afe5f3abe73f2b68fe085aa959bd8cb4969c7b1068093e80846d67
2017-03-24 09:18:36 received block a677dbb52956cf59f7076f022353c9e57eed5532c7bcd03331d6ce0d5429c672
2017-03-24 09:18:36 ProcessBlock: ORPHAN BLOCK, prev=2a1e29bcda24c83db9e6ac2d654ad889d562feeca173fa45dc847984d996cc77
2017-03-24 09:18:38 UPnP Port Mapping successful.
2017-03-24 09:18:58 accepted connection 176.31.122.178:59307
2017-03-24 09:18:58 send version message: version 99010, blocks=26685, us=130.83.137.28:29100, them=176.31.122.178:59307, peer=176.31.122.178:59307
2017-03-24 09:18:58 Added time data, samples 22, offset +1 (+0 minutes)
2017-03-24 09:18:58 Moving 176.31.122.178:29100 to tried
2017-03-24 09:18:58 receive version message:Satoshi:3.0.0.9/: version 99008, blocks=27126, us=130.83.137.28:29100, them=176.31.122.178:29100, peer=176.31.122.178:59307
2017-03-24 09:20:12 RandAddSeed() 206544 bytes
2017-03-24 09:20:12 received block bed542e85ddb1f85c2388a60179d82b183fc720c31ae343d2791abc56eb5d654
2017-03-24 09:20:12 ProcessBlock: ORPHAN BLOCK, prev=a677dbb52956cf59f7076f022353c9e57eed5532c7bcd03331d6ce0d5429c672
2017-03-24 09:20:50 received block 30ebaa82d35db34d5d18eefbd5bbb9c3902c29a4959badb596cf0158aa321d59
2017-03-24 09:20:50 ProcessBlock: ORPHAN BLOCK, prev=bed542e85ddb1f85c2388a60179d82b183fc720c31ae343d2791abc56eb5d654
2017-03-24 09:20:51 received block b1d0f85c0c59a4ae3b4b85a23ed98e112119b4aec8de288e532d0b93fd157543
2017-03-24 09:20:51 ERROR: CTransaction::CheckTransaction() : Error: Node does not have mint zerocoin to verify, please wait until
2017-03-24 09:20:51 ERROR: CheckBlock() : CheckTransaction failed
2017-03-24 09:20:51 ERROR: ProcessBlock() : CheckBlock FAILED
2017-03-24 09:20:51 received block 1bdc95e25bfb1d0dc034149190b5faaae04447b6216c7a0c5fd6f894020b3a11
2017-03-24 09:20:51 ERROR: CTransaction::CheckTransaction() : Error: Node does not have mint zerocoin to verify, please wait until
2017-03-24 09:20:51 ERROR: CheckBlock() : CheckTransaction failed
2017-03-24 09:20:51 ERROR: ProcessBlock() : CheckBlock FAILED
2017-03-24 09:21:08 AcceptToMemoryPool: 92.127.254.229:29100Satoshi:3.0.1/ : accepted 0c1ca1f99adbc93ed9241c7b46a633af3fc2ea68d7a63fadb8b518215a26e892 (poolsz 9)
2017-03-24 09:21:08 AcceptToMemoryPool: 178.23.227.175:29100Satoshi:3.0.1/ : accepted d521286f70c82c4bcf108893605b71edb556b91e9400bb1f3fd53784207d389f (poolsz 10)
2017-03-24 09:21:09 received getdata for: tx 0c1ca1f99adbc93ed9241c7b46a633af3fc2ea68d7a63fadb8b518215a26e892
2017-03-24 09:21:11 mempool.countZCSpend = 0
2017-03-24 09:21:11 CreateNewBlock(): total size 3407
2017-03-24 09:22:12 accepted connection 106.127.163.227:40035
2017-03-24 09:22:12 send version message: version 99010, blocks=26685, us=130.83.137.28:29100, them=106.127.163.227:40035, peer=106.127.163.227:40035
2017-03-24 09:22:12 Added time data, samples 23, offset +37 (+0 minutes)
2017-03-24 09:22:12 nTimeOffset = +1 (+0 minutes)
2017-03-24 09:22:12 Moving 106.127.163.227:29100 to tried
2017-03-24 09:22:12 receive version message:Satoshi:3.0.0.9/: version 99008, blocks=27128, us=130.83.137.28:29100, them=106.127.163.227:29100, peer=106.127.163.227:40035
2017-03-24 09:23:09 received block a5751e762eaa7f9e5fee05ac729834ec5143354a25cd741bc6d4eb008cb09584
2017-03-24 09:23:09 ProcessBlock: ORPHAN BLOCK, prev=30ebaa82d35db34d5d18eefbd5bbb9c3902c29a4959badb596cf0158aa321d59
2017-03-24 09:23:15 received block b1d0f85c0c59a4ae3b4b85a23ed98e112119b4aec8de288e532d0b93fd157543
2017-03-24 09:23:15 ERROR: CTransaction::CheckTransaction() : Error: Node does not have mint zerocoin to verify, please wait until
2017-03-24 09:23:15 ERROR: CheckBlock() : CheckTransaction failed
2017-03-24 09:23:15 ERROR: ProcessBlock() : CheckBlock FAILED
2017-03-24 09:23:15 received block 1bdc95e25bfb1d0dc034149190b5faaae04447b6216c7a0c5fd6f894020b3a11
2017-03-24 09:23:15 ERROR: CTransaction::CheckTransaction() : Error: Node does not have mint zerocoin to verify, please wait until
2017-03-24 09:23:15 ERROR: CheckBlock() : CheckTransaction failed
2017-03-24 09:23:15 ERROR: ProcessBlock() : CheckBlock FAILED
2017-03-24 09:23:37 Flushed 1005 addresses to peers.dat 46ms
2017-03-24 09:24:01 received block 79aaf6523c45132f4fd89af25bc2715fc2efa88e36226b955e098bf6e6790388
2017-03-24 09:24:01 ProcessBlock: ORPHAN BLOCK, prev=a5751e762eaa7f9e5fee05ac729834ec5143354a25cd741bc6d4eb008cb09584
2017-03-24 09:24:09 AcceptToMemoryPool: [2001:0:9d38:6abd:2cc4:3bcc:3c37:aa0]:29100Satoshi:3.0.1/ : accepted 9a388454a4a07bb3ea88318664a0a390695ad1dd9468d0f9509e940c40a254c3 (poolsz 11)
2017-03-24 09:24:09 received getdata for: tx 9a388454a4a07bb3ea88318664a0a390695ad1dd9468d0f9509e940c40a254c3
2017-03-24 09:24:09 received getdata for: tx 9a388454a4a07bb3ea88318664a0a390695ad1dd9468d0f9509e940c40a254c3
2017-03-24 09:24:13 mempool.countZCSpend = 0
2017-03-24 09:24:13 CreateNewBlock(): total size 3633
tried with only 2 connections, only one, unlimited and all 3.0.1.0 nodes from cryptoid added as addnode, not working :/