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Happy New Year everybody!
Describe the issue
I have installed Bitcoin Core (64-bit) and changed the data directory to one on my NAS. I ran Bitcoin Core and after 2 days of synchronizing the Bitcoin Core window shows "Up to date". The program exits without any problems.
After each following regular startup however Bitcoin Core (64-bit) reports "Error opening block database. Do your want to rebuild the block database now?" and I have to abort the operation.
When I install Bitcoin Core again and choose to "Run Bitcoin Core (64-bit)" everything works again, including the already synchronized blocks.
Can you reliably reproduce the issue?
If so, please list the steps to reproduce below:
- Start Bitcoin Core
- Message: "Error opening block database. Do your want to rebuild the block database now?"

- Run the Bitcoin Core installer again: "bitcoin-0.13.1-win64-setup.exe"
- Choose "Run Bitcoin Core (64-bit)", everything works again

What version of bitcoin-core are you using?
Bitcoin Core version v0.13.1 (64-bit)
Machine specs:
- OS: Windows 10 Pro
- CPU: Intel Core i7
- RAM: 8.00 GB
- Disk size: 256GB & 4TB
- Disk Type (HD/SDD): SSD & HD
Any extra information that might be useful in the debugging process.
This is how the debug.log looks like when the error occurs: Bitcoin debug_not working on regular startup.txt
This is how the debug.log looks like after a reinstall with Bitcoin Core correctly running: Bitcoin debug_working again after fresh install.txt