Recordings will not play within Netcam Studio 1.9.5.0

I have some recordings that will not play from within Netcam, but the same files will play perfectly well directly in Windows 10. (VLC V 3.0.18 Vetinari)

I assume you mean that it do not find VLC. Windows keep track of where programs are saved. Make sure that VLC is installed in its default library.

No, that’s not the problem. VLC is properly installed and most of my recordings play properly. The problem files are usually comparitively long (5 minutes or more) and always (so far) from 1 particular camera. So far, no issues with a second camera with recordings of similar length.

The VLC error message is:

'Your input can’t be opened:

VLC is unable to open the MRL ‘http://192.168.0.30:8100/Library/202304140057?authToken=be0c55cf-dc91-4347-974a-7d8a968a84f0’. Check the log for details.’

I suggest this.
In the Setting for Library do a reindex of the Library.
If still problems keep that camera installed. Add the same camera again. That will generate a new Token. Disable the “old camera”. If the new setup works delete the “old camera”.