Should not be an issue. Place all the clips to be exported on a track in the new sequence. Export sees all tracks in the sequence. Tested that here via the method described above and it succeeded.
As to no video, share a clip or two that has the issue.
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.**
What version of VP is being used? Install this one and see if that makes a difference.
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.