Dear Regina1,
Can you please enable writing the log to the external file, re-start Metashape and try to reproduce the problem with the texture generation?
If the crash occurs again, please send the log to support@agisoft.com or post it here, if it doesn't contain any sensible information.
Without having any additional details I would assume that the problem is related to the GPU driver (you can check, if you could complete the same operation, having the graphic cards disabled in the GPU Preferences tab of Metashape window).