[SOLVED] Problem import

I solved the UTF-8 issue at the time. Even the import with a sample dataset fails. I don't use all fields for import. Are there mandatory fields that are required as a minimum?

I tested extra for you:
The format of the imported file must be UTF-8-BOM!
you wrote:

COM_JEM_IMPORT_NUMBER_OF_ROWS_ERROR [Id events: 2023-03-01,2023-03-03,2023-03-04]

this is strange: event IDs are never dates!
I tested with deleting some fields, but never did get such result.
So I would say, you should test the import with all fields, even when they are empty
EDIT:
can you send me (a part of) your csv?

COM_JEM_IMPORT_NUMBER_OF_ROWS_ERROR is defined in \administrator\components\com_jem\language\en-GB\en-GB.com_jem.ini
Three questions:
1. What JEM version do you install when you have this error?
2. Did you have JEM tables before you installed this version?
3. Do you have done any change to the content of JEM 2.3 export file?

Last, you could copy the first lines of the export/import csv file that you get of JEM 2.3.x.

I solved the problem. several fields are mandatory.
dates;enddates;title;introtext;published;version;fulltext;metadata;categories;access