The fist time this error occurred it was updating blocks (2 days were left) and suddenly a window pop up reading a fatal internal error occurred ("Un error interno fatal ocurrió, ver debug.log para detalles"); now when I open the program it just says that after verifying the blocks, and when starting new threads.

debug.log (there were several blank lines before this, so I just copied this part):

2016-11-22 01:24:53 Bitcoin version v0.13.1.0-45f61ea-dirty
2016-11-22 01:24:53 InitParameterInteraction: parameter interaction: -whitelistforcerelay=1 -> setting -whitelistrelay=1
2016-11-22 01:24:53 GUI: QMetaObject::connectSlotsByName: No matching signal for on_toggleNetworkActiveButton_clicked()
2016-11-22 01:24:53 GUI: "registerShutdownBlockReason: Successfully registered: Bitcoin Knots didn't yet exit safely..."
2016-11-22 01:24:54 Default data directory C:\Users\emmanuel\AppData\Roaming\Bitcoin
2016-11-22 01:24:54 Using data directory C:\Users\emmanuel\AppData\Roaming\Bitcoin
2016-11-22 01:24:54 Using config file C:\Users\emmanuel\AppData\Roaming\Bitcoin\bitcoin.conf
2016-11-22 01:24:54 Using rw config file C:\Users\emmanuel\AppData\Roaming\Bitcoin\bitcoin_rw.conf
2016-11-22 01:24:54 Using at most 125 connections (2048 file descriptors available)
2016-11-22 01:24:54 Using 2 threads for script verification
2016-11-22 01:24:54 Using BerkeleyDB version Berkeley DB 4.8.30: (April 9, 2010)
2016-11-22 01:24:54 Using wallet wallet.dat
2016-11-22 01:24:54 init message: Verificando monedero...
2016-11-22 01:24:54 scheduler thread start
2016-11-22 01:24:54 CDBEnv::Open: LogDir=C:\Users\emmanuel\AppData\Roaming\Bitcoin\database ErrorFile=C:\Users\emmanuel\AppData\Roaming\Bitcoin\db.log
2016-11-22 01:24:54 Bound to [::]:8333
2016-11-22 01:24:54 Bound to 0.0.0.0:8333
2016-11-22 01:24:54 Cache configuration:
2016-11-22 01:24:54 * Using 2.0MiB for block index database
2016-11-22 01:24:54 * Using 8.0MiB for chain state database
2016-11-22 01:24:54 * Using 290.0MiB for UTXO set (plus up to 286.1MiB of unused mempool space)
2016-11-22 01:24:54 init message: Cargando el índice de bloques...
2016-11-22 01:24:54 Opening LevelDB in C:\Users\emmanuel\AppData\Roaming\Bitcoin\blocks\index
2016-11-22 01:24:54 Opened LevelDB successfully
2016-11-22 01:24:54 Using obfuscation key for C:\Users\emmanuel\AppData\Roaming\Bitcoin\blocks\index: 0000000000000000
2016-11-22 01:24:54 Opening LevelDB in C:\Users\emmanuel\AppData\Roaming\Bitcoin\chainstate
2016-11-22 01:24:56 Opened LevelDB successfully
2016-11-22 01:24:56 Using obfuscation key for C:\Users\emmanuel\AppData\Roaming\Bitcoin\chainstate: c44112a85ca594e6
2016-11-22 01:25:01 LoadBlockIndexDB: last block file = 684
2016-11-22 01:25:01 LoadBlockIndexDB: last block file info: CBlockFileInfo(blocks=133, size=118190385, heights=439706...439931, time=2016-11-19...2016-11-21)
2016-11-22 01:25:01 Checking all blk files are present...
2016-11-22 01:25:02 LoadBlockIndexDB: transaction index disabled
2016-11-22 01:25:02 LoadBlockIndexDB: hashBestChain=000000000000000002001298f9ad5620cbac7cff6e17cac899924992eabf85ce height=439743 date=2016-11-20 02:35:13 progress=0.992430
2016-11-22 01:25:02 init message: Verificando bloques...
2016-11-22 01:25:04 init message: Verificando bloques...
2016-11-22 01:25:04 Verifying last 6 blocks at level 3
2016-11-22 01:25:04 [0%]...[16%]...[33%]...[50%]...[66%]...[83%]...[99%]...[DONE].
2016-11-22 01:25:07 No coin database inconsistencies in last 7 blocks (11746 transactions)
2016-11-22 01:25:07 block index 12871ms
2016-11-22 01:25:07 init message: Cargando monedero...
2016-11-22 01:25:07 nFileVersion = 130100
2016-11-22 01:25:07 Keys: 0 plaintext, 204 encrypted, 204 w/ metadata, 204 total
2016-11-22 01:25:07 wallet 11ms
2016-11-22 01:25:07 mapBlockIndex.size() = 440002
2016-11-22 01:25:07 nBestHeight = 439743
2016-11-22 01:25:07 setKeyPool.size() = 99
2016-11-22 01:25:07 mapWallet.size() = 1
2016-11-22 01:25:07 mapAddressBook.size() = 3
2016-11-22 01:25:07 init message: Cargando direcciones...
2016-11-22 01:25:07 torcontrol thread start
2016-11-22 01:25:07 ERROR: ReadBlockFromDisk: Deserialize or I/O error - ReadCompactSize(): size too large at CBlockDiskPos(nFile=684, nPos=5409179)
2016-11-22 01:25:07 *** Failed to read block
2016-11-22 01:25:07 Loaded 61176 addresses from peers.dat 410ms
2016-11-22 01:25:07 init message: Cargando banlist...
2016-11-22 01:25:07 init message: Starting network threads...
2016-11-22 01:25:12 Failed to connect best blockAddLocal([2001:0:9d38:90d7:403:3780:4a5b:b0d4]:8333,1)
2016-11-22 01:25:12 Discover: DESKTOP-1A88148 - 2001:0:9d38:90d7:403:3780:4a5b:b0d4
2016-11-22 01:25:12 dnsseed thread start
2016-11-22 01:25:12 net thread start
2016-11-22 01:25:12 addcon thread start
2016-11-22 01:25:12 opencon thread start
2016-11-22 01:25:12 msghand thread start
2016-11-22 01:25:12 init message: Se terminó de cargar
2016-11-22 01:25:12 tor: Thread interrupt
2016-11-22 01:25:12 scheduler thread interrupt
2016-11-22 01:25:12 torcontrol thread exit
2016-11-22 01:25:12 msghand thread interrupt
2016-11-22 01:25:12 addcon thread interrupt
2016-11-22 01:25:12 opencon thread interrupt
2016-11-22 01:25:12 dnsseed thread interrupt
2016-11-22 01:25:12 net thread interrupt
2016-11-22 01:25:12 Shutdown: In progress...
2016-11-22 01:25:12 StopNode()
2016-11-22 01:25:13 Shutdown: done