Try doing a complete wipe and new installation: pluck-out your Save Games Folder, Track Folder, Object Folder to a separate location; perform a thorough Uninstall and shred the entire (remaining) OpenRCT2 Folder; reinstall from scratch; restore those Folders that were set aside.
The Letter 'L'
in Problems, Bugs and Feedback
Posted
I just re-installed and it fixed the issue.
Thanks