Hello Möller,
If possible please send E57 that crashes the application to support@agisoft.com (as a download link, if the file is large), so that we could check it on our side.
As for the PTS file, I assume that the first line of the file doesn't contain the number of points to be imported, as expected by Metashape importer.
Please also make sure that you are using latest Metashape Pro release version.