writer crashes when trying to execute mail merge

Win 7, LibreOffice When trying to do a mail merge, writer crashes. There is no error indication given, so it is impossible for me to determine what is wrong. This happens both with the wizard and the print function. The associated data is a spreadsheet and appears correct when the filters are applied. It appears that the crash occurs with the first record. Again there is no error condition being reported… just that LO has crashed. I have tried searching for this problem… there are many questions concerning mail merge, but few answers. If I am going to give MS Office the boot, I need to solve this issue.

I had the same problem after I copied a field line to the bottom line. The problem seemed to be that this line was protected. Deleting it and creating the same field fresh solved my problem.

I had a similar problem. I have a Writer template, and a Calc spreadsheet for database fields to be merged into the template.
Today when selecting the mail merge wizard from the Tools menu, it appeared as a white rectangle with no contents. When trying to close it, LibreOffice crashed. I discovered that this was my own fault. I had erased a database file that LibreOffice had created automatically. LibreOffice obviously automatically creates a database (libreOffice base odb) file in the local user’s Documents root of Windows, when setting up the data source.
I restored the database file (it was still in the Recycle bin) and the mail mere was functioning again.

Now I will have to remember not to delete that file! And also to select “Print…” from the File menu, since it’s simpler than the Mail Merge Wizard which seems to be more unforgiving and overly complicated. With a year since the last time I used it, I had forgot exactly how to deal with this (again)… Need to remember: Just “Print…” and don’t delete that file…

I had the same problem with LibreOffice 6.0.2 and nothing helped even after I removed and recreated the datasource many times.

Eventually I downgraded to LibreOffice and it worked with the same Writer/Calc files. Looks like a bug in LibreOffice 6 to me.