Lost contacts in outlook after each new insider build

[Alfred]

why do I lose contacts in outlook whenever I get a new insider version?
Do I need to export them to a PST file on another hard drive first before downloading and installing new build

 

[Bighorn]

Which version of Outlook? Rather than export the .pst file have you looked for an Export of only the Contacts as a .csv file useful for the Import? Since the .csv file is essentially a spreadsheet it can be viewed in other programs.

 

[Alfred]

Which version of Outlook? Rather than export the .pst file have you looked for an Export of only the Contacts as a .csv file useful for the Import? Since the .csv file is essentially a spreadsheet it can be viewed in other programs.

Thanks for that- I will try it
the version is office 365 ( I think outlook 2017)