Printing preview blanks may be caused by cache exceptions or improper settings. 1. Clear UC browser cache and restart; 2. Check the paper size, direction and turn off options such as "Hide Background Graphics"; 3. Save the web page as PDF and print with PDF application; 4. Try to enable desktop mode or replace it with Chrome or Edge browser to print to eliminate compatibility issues.

All or delete individual download records to manage privacy. You can clear all records by setting → Privacy and Security → Clear browsing data, check the download content and select all time; or visit the chrome://downloads page, click the three-point button on the right side of a specific download item, and select Remove from the list to achieve single or batch deletion.

There are three ways to change the default PDF opening method to your desired application: through File Explorer, System Settings, or Control Panel. First, you can right-click on any PDF file and select "Open with" and check "Always use this app"; secondly, enter the "Default Application" setting through [Win I] and specify a program for .pdf; you can also manually associate it through the "Default Program" function of the control panel. If it is still changed after setting it, you need to check whether the security software has reset the association, and make sure that the PDF reader's own settings have been set to default to avoid conflicts between multiple PDF software and lead to unstable association.

First, turn on the desktop mode through the built-in menu. If it is not feasible, manually modify the UA to computer mode. Finally, you can use other browsers to access it.

1. Turn on the reading mode of UC Browser to bypass copy restrictions. Click the book icon and long press the text to copy; 2. Disable JavaScript to remove script protection. Go to settings to turn off this function and refresh the page; 3. Use the webpage snapshot function to load content in a simplified form, peel off the control script and freely select to copy; 4. Trigger text re-rendering through the translation function to invalidate the anti-copy script to complete the copy.

If Google Chrome freezes, freezes, or crashes, you can try adjusting the hardware acceleration settings. First turn it on or off through the "Use Hardware Acceleration Mode" switch in the browser settings, and restart the browser; if the problem persists, go to the chrome://flags page, search for gpu-related options, disable experimental features such as Hardware-accelerated videodecode, GPUrasterization, and Zero-copyrasterizer, and then restart the browser to apply the changes.

1. To turn off the ad filtering function of 360 browser, you need to go to Settings → Extended Function → Turn off the ad filtering switch; 2. Uncheck the recommended items for today's preferred, hot news, etc. in the laboratory; 3. Remove third-party ad blocking plug-ins such as Adblock through extension management; 4. Check privacy and security settings, disable pop-up blocking and related filtering permissions; 5. If it is still invalid, you can reset the browser to the default settings to completely clear the filtering rules.

Log in with a QQ account to synchronize multiple devices, and it is recommended not to exceed 3 devices; WeChat login only supports single device online, which is suitable for occasional use. Choose a more appropriate method based on your usage habits.