Author: Bob Lin

Situation: One of users brings his laptop to the office. He can ping any websites, but can’t access them. Other office computers don’t have this issue.

Troubleshooting: we find the firewall blocking non-domain computer to access the Internet.

Situation: the small company just setup a new PC. Then their network is down.

Troubleshooting: We found the cable connecting between the computer and switch is bad. After plugging the cable to the switch, all ports led are blinking, which shutdown the switch and whole network.

Situation: the small company just setup a new PC. However, it can’t access the LAN and Internet.

Troubleshooting: We found the cable connecting between computer and switch is bad. After plugging the cable to the switch, all ports led are blinking. Replacing another cable fixes the problem.

Situating: After installing Windows 10 version 2004, the user gets BSOD: RDR_FILE_SYSTEM.

Resolution:

Scanning the web religiously I found a reference which suggested the problem was in the mrxsmb20.sys file itself, that it was being overwhelmed. Several people suggested downloading a copy from another system of the file and bringing it over (tried, major permissions struggle but do-able), it failed. But one guy in the middle of a long string of diagnisis and suggestions suggested

Disabling offline file synchronization.

Situation: The client has Synology 1618. They can’t open Package Center: with this message: “connection failed. please check your network and time settings”

Troubleshooting: on Paloalto Firewall Monitor, we find the traffic to 52.114.x.x was denied by security policy. IP locator points the IP located in Taiwan, which the firewall blocks.

The resolution is excluding the IP address to the policy. This is the step by step video.

How to unblock a country in Outbound block policy in Palo Alto Firewall

Or add Synology website into Security policy. Please refer to this post:

How to allow accessing blocked countries’ URL in paloalto firewall

Other resolution found online.

Resolution 1: Based on Synology:

1. Please make sure the DNS Server and Gateway settings are properly configured on Diskstation. You can set up DNS server to 8.8.8.8 or 8.8.4.4 (Google’s public Server) in Control Panel > Network.
Usually, the gateway should be your router’s IP address, we suggest to use a Public DNS server instead of your Router.

2. Please go to Control Panel > Network > Network Interface > edit > IPv6, change the setting from “Auto” to “Disable”;

3. Please go to Control Panel > Network > Network Interface > edit > IPv4, change the setting from “DHCP” to “Manual”;
Make sure the MTU value for the interface is the default one : 1500.

4. Please go to DSM > Control Panel > Regional Options and make sure the time sync with NTP service is right.”

It may take a few hours to fix the problem. Or you can restart Synology.

Resolution 2: corporate SSL settings

This problem may also be caused by corporate SSL proxies. You can check this with curl https://payment.synology.com/api/getPackageListv1.php (from the shell prompt on your NAS). The error will be obvious. To fix it, you need to add your proxy certificate chain to /etc/ssl/certs/ca-certificates.txt. BE CAREFUL NOT TO OVERWRITE IT!

For completeness, you’re supposed to place the individual CA certificates in the chain in /usr/share/ca-certificates. I created a “work” subdirectory. Then symlink those certificates (ending in .crt) to /etc/ssl/certs (ending in .pem). Lastly, cat Company*.pem >> /etc/ssl/certs/ca-certificates.txt (assuming all your certs begin with “Company”). Note the use of >> in the command. This appends, while a single > will overwrite (not good).

Package Center will need to be relaunched to clear the error.

Resolution 3: I ended up fixing my issue by updating my DDNS certificate.

I went to “Control Panel=>Security=>Certificate” then right clicked my DDNS certificate and clicked “Renew certificate”.

Prior to this I tried all the suggestions (manually set DNS to Google, updated time, etc).

Resolution 4: from Synology support: Please be aware that if you have firewall rules which might be blocking IP address, via Geo location we would like for you to disable this feature for sites in the Taiwan area. As this is the location of our Headquarters and Package Server location. If you have any special firewall rules on your NAS, Control Panel>Security>Firewall. We would recommend disabling these temporarily while you test the connection for Package Center.

Problem 1: When reinstalling Windows 10 on a pre-installed Windows 10 computer, the user doesn’t the option ‘I don’t have a key’ and ‘Do this later’

Troubleshooting: In most cases, it is a different Windows 10 Edition, for example the original installed edition is Windows 10 Home. The user tries to install Windows 10 Professional.

Problem 2: When upgrading Windows 7/8 to windows 10 on a pre-installed Windows computer, the user doesn’t the option ‘I don’t have a key’ and ‘Do this later’

Troubleshooting: In most cases, it is a different Windows Edition, for example the original installed edition is Windows 8.1 Home. The user tries to install Windows 10 Professional.

Problem 3: The product key used on this device didn’t work with this edition of Windows. You might need to get in touch with the store or company you bought Windows from, enter a different product key, or go to the Store to buy genuine Windows. Error code: 0xC004F212, 0x8007232B, 0xC004F074, 0xC004F038, 0x8007007B

Troubleshooting: Make sure you are installing the same Windows 10 Edition.

Problem 4: Windows reported that the hardware of your device has changed. Error code: 0xC004F211

Troubleshooting: In this case, the Windows license is associated with your device hardware which has been changed, for example replacing the motherboard,

Problem 5: Windows reported that no product key was found on your device. Error code: 0xC004F213

Troubleshooting: Again, the Windows license is associated with your device hardware which has been changed, for example replacing the motherboard,

Problem 6: “Your Windows License Will Expire Soon” warning or error code: 0xC004C020

Troubleshooting: This may occur if you have a volume license client installed, which is managed by your organization. You should contact your system administrator for assistance.

Problem 7: Activate license error code: 0x803f7001.

Troubleshooting: Make sure the hardware has not been changed or you are installing the same Windows Edition.

Problem 8: Activate license error code: 0x800704cF, 0xC004C003, 0xC004F034, 0xC004F210, 0xC004E016, 0xC004F210, 0xC004F00F

Troubleshooting: Make sure the hardware has not been changed or you are installing the same Windows Edition. Also pleas make sure you enter correct license keys.

Problem 9: Activate license error code: 0xC004FC03, 0x8007267C, 0xD0000272, 0xC0000272, 0xc004C012, 0xC004C013, 0xC004C014

Troubleshooting: That could be an Internet issue or firewall blocking the connection. Make sure that you’re connected to the internet and your firewall isn’t blocking Windows from activating.

Probl1m 10: all other error code:

0xC004C060, 0xC004C4A2, 0xC004C4A2, 0x803FA067L, 0xC004C001, 0xC004C004, 0xC004F004, 0xC004C007, 0xC004F005, 0xC004C00F, 0xC004C010, 0xC004C00E, 0xC004C4A4, 0xC004C4A5, 0xC004B001, 0xC004F010, 0xC004F050

Troubleshooting: Quoted from Microsoft wesite:

• You entered a product key that can’t be used to activate Windows. Enter a different product key or buy a new product key.
• You upgraded to Windows 10, but the activation servers were busy. If you upgraded from an activated copy of Windows 7 or Windows 8.1, your copy of Windows 10 will be automatically activated, or you can wait a while and then select Activate. If you continue to have problems with activation, contact customer support.
• You upgraded to Windows 10 using the free upgrade offer, but Windows 10 isn’t activated after a reinstall. Your copy of Windows 10 should automatically be activated as long as you didn’t make any significant hardware changes to your device (such as replacing the motherboard). If you continue to have problems with activation, contact customer support.

Problem 11: Activate license error code: 0xC004E028, 0xC004C008, 0xC004C770, 0x803FA071

Troubleshooting: the license may be used by someone already or activation is already in the process.

Problem 12: Activate license error code: 0x80072F8F

Troubleshooting: that could be time issue. If the date and time for the device is incorrect, or Windows has trouble connecting to the online activation service, you may receive this error code.

Problem 12: Activate license error code: 0xC004E003, 0x80070652

Troubleshooting: The system files may be damaged. run SFC tool to fix it. PLease refer to this post:

Run DISM and SFC to repair missing or corrupted system files

Problem 12: Activate license error code: 0x80004005, 0x87e10bc6

Troubleshooting: Activation troubleshooting tool may fix this problem. Select Start  > Settings  > Update & Security  > Activation , and then select Troubleshoot to run the Activation troubleshooter. 

Situation: when using the Zoom, the video is disabled. If click on it, you get this message: Cannot start video. Failed to start the video camera. Please select another video camera in the Settigns.

Troubleshooting: 1. Install the latest Camera driver.

2. Make sure that all other programs that utilize the camera are not using the camera or are closed.

3. Restart your computer.

4. Uninstall the Zoom client and reinstall the latest version from Zoo.us

Normally, BSOD indicates problems with the computer’s hardware or hardware driver software. Here are some troubleshooting options.

Option 1: Unplug all external devices except keyboard and mouse. Try to start it again.

Option 2: Run DISM & SFC scan if you can login Windows. PLease refer to this post for more details:

Run DISM and SFC to repair missing or corrupted system files

Option 3: Run Clean boot if you can login Windows.

Option 4: Run Safe mode to troubleshoot the problem. Please refer to these posts:

Boot in Windows 10 Safe Mode by interrupting the startup process three times

How to boot into Windows 10 Safe Mode in black screen

Option 5: Run System Restore. Please refer to this post for more details:

How to Use Windows System Restore

Situation: After installing Windows 10 version 2004 or KB4557957, some printers may be unable to print. Here are some symptoms: 1) The print spooler might have an error; 2) The apps closes unexpectedly when attempting to print; 3) You might encounter issues with the apps you are attempting to print from; 4) You might receive an error from the app or the app may close unexpectedly

Resolution 1: Install update KB4567523 which is a cumulative update.

Resolution 2: Install latest printer driver.

resolution 1: Upgrade the Bluetooth driver.

1. In search bar, type Device Manager, and then hit Enter.
2. Click on Bluetooth.
2. Right-click on the Bluetooth driver.
3. Select Update this driver.

Resolution 2: Uninstall and re-install the Bluetooth.

1. In search bar, type Device Manager, and then hit Enter.
2. Click on Bluetooth.
2. Right-click on the Bluetooth driver.
3. Select Uninstall this driver.

4. Re-enable the devices. Go back to Device Manager. Right-click on Bluetooth then select scan for hardware changes. It should automatically detect the Bluetooth drivers and reinstall them.

Resolution 3: If the issues continues, you may want to rollback to the previous version. Please refer to this post:

How to restore the previous version of Windows 10