While using 7.03, you say that things changed That hints at something amiss with your PC. What are its specs: CPU, GPU/video adapter, RAM, free space on C:?
Try these measures...
Update the video driver and Direct-X, if necessary. https://www.nch.com.au/kb/10265.html
Confirm that the drive is free of errors. In the W10 search box (bottom-left) type COMMAND <enter>. At the right click RUN AS ADMINISTRATOR. In the black box that appears type chkdsk c:
At the end of this quick process it should report "Windows has scanned the file system and found no problems." No further action is required. If it does report issues, run this command: chkdsk c: /F This could take some time and require a reboot.
In Windows Explorer (the file manager) right-click the C drive and click PROPERTIES. Click Disk Cleanup.
Close all other programs while running Videopad.
Test this Videopad 10.12 version. For licensed users upgrades are free for up to six months from purchase date. After that, VP will continue to fully function but a fee will be required in order to register the newest. Retain your old install file and registration info.
When invoking effects with <alt-V> expect a slight delay the first time it's used after an install. Thereafter the efx window should pop up immediately. The shortcut to drop a clip from the bin to the timeline is <ctrl-W>. <ctrl-shift-V) brings up the text editor.
Test Videopad on another PC, if available. It's not inconceivable that the PC has been compromised with a virus.
Please report your findings here.