2 important things here.
1) first download the official 1.5.2 from netcam studio website or from this thread:
it was 4 revisions of this 1.5.2 version going here in the community / forum and in one of them i had to fix a problem with timelapse movies not being created properly following your message here and a few tests and my end so please ensure you have the latest / official one that was released on netcamstudio.com
2) if you chose stillimage as target then you won't be able to access it through the gallery (in netcam studio or the web client). You need to generate a timelapse movie to be able to access it from ncs library otherwise in the ncs gallery you'll just get a single picture (but you can still retrieve manually all the other pictures that were collected on your hdd in the library/timelapse folder as it's the purpose of this mode, it's just not integrated through the library / ui)