What version of Videopad is running? Test the latest. 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 is required in order to register the newest. Retain your old install file and registration info. If there's an issue, you can always revert.
First thing, prior to loading, go to OPTIONS | DISK tab and Clear Unused Cache Files.
Please share a file or two that will not load, and someone here will take a look at them. Upload the file/s to a free server, such as Google Drive or MS OneDrive, right-click the link and Share. Copy the result and paste it here or to me in a Private Message via the mail envelope in the top-right corner of this forum. When using Google Drive, if necessary change "restricted" to "anyone with link can view.**