Audio editing in Wavlab Audio Montage suddenly out of operation

When editing a large audio file (96 kHz / 24 bit / 1h20min) to create the final CD (in Audio Montage) I used cutting and deleting as usual. From one minute to the next I was not able to use either the mouse operated ‘Split at cursor position’ nor the hokey (S). Moreover, ‘Erase section in clip’ was not possible as well. I tried restarting the program, restarting the PC, resetting the program, nothing helped. Playback and placing marker, jumping to marker, etc. all’s possible. Any advice? What went wrong?

I must say I have no cue. Do these functions work on another montage?

To be honest, I noticed yesterday that in the montage, the cut in the first part of the wave file works without any problems; it is only after about minute 25 that no more cuts can be made. The montage contains two stereo tracks with clips from a single source file. It is a live recording, whereby I distribute the individual songs as clips on the two tracks alternately after cutting and then edit them. At the moment, the uncut rest of the recording is in the second track from minute 25. Moving it to track 1 is possible but does not help.

I just used ‘Clone and substitute’ and now it works. Can anyone tell me why?

The only way to know why is to get a full copy of the montage. Even so, if the problem is caused by some third-party plugins, then it won’t be possible to know.

That would be possible, on the other hand quite a lot of effort. I have a vague suspicion: I had an error (“crackling”) in the source file after minute 25, which I fixed by ‘editing’ (opening the wave file from the montage), then I saved the original file, closed it and the result was of course transferred to the montage (as expected). However, the entire source file was ‘renewed’ and not only the period after minute 25. Therefore, I stil do not understand why I could stil edit before minute 25 and not after minute 25. Well, I will now continue my work and hope that this was the necessary operation.
Thank you very much for your quick and kind reply.

Do you have the rf64 option checked? Preferences>Audio Files>File>Support RF64 File Format It is a large file and maybe over 2 gig at 96/24

I think only PG would likely know if this could have an influence on your situation.