Subtitles are working fine in the latest version. Download and install it. 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.
The subtitles will not change the video. So if there is a black bar, that is due to the resolution or sizing of the video. To change the subtitle appearance click the Format tab in the subtitle configuration box.
If none of this helps, please share your project. It's easy, quick and can be private. Someone will take a look, and recommend a fix. Follow these steps carefully...
Back up --- With your project on the timeline, click on MENU at the top-left. Click FILE|BACK UP PROJECT FILES TO FOLDER. Choose a folder and SELECT FOLDER.
Upload --- Upload the saved, numbered FOLDER. Use a free server - Google Drive, MS OneDrive, etc.* Do NOT upload the individual VPJ or export file.
Get link --- Get a public link. If using Google Drive click GET SHAREABLE LINK. Change "restricted" to "anyone with the link can view" Click COPY LINK | DONE.
Share --- Paste that link here, or click the folder at the top-right of this forum to message it privately to me. It won't be shared.
* Before uploading, right-click the folder, click PROPERTIES. Look at the File Size to confirm that it's not too big for the free space on the server.