Why does LiDAR data throw an error after being saved and reopened? " Failed to add imaged .... [err:7134] "

Does anyone know why RC throws this error every time I reopen a saved project with LiDAR data? There are no Chinese characters in the file paths.

The .lsp files, which were converted from .ply by RC, actually display fine when imported into a new project. But once the project is saved, it can never be opened again.