BUG #16182: Error in logs from "renaming temporary statistics"

The following bug has been logged on the website:

Bug reference:      16182
Logged by:          Johan Fredrik Øhman
Email address:      johanfo@gmail.com
PostgreSQL version: 12.1
Operating system:   Microsoft Windows 2019 Server
Description:

For some weird reason I cannot understand, I keep getting this in the
logs:

2020-01-02 07:22:51.461 CET [1400] LOG:  could not rename temporary
statistics file "pg_stat_tmp/global.tmp" to "pg_stat_tmp/global.stat":
Permission denied
2020-01-02 07:28:31.262 CET [1400] LOG:  could not rename temporary
statistics file "pg_stat_tmp/global.tmp" to "pg_stat_tmp/global.stat":
Permission denied
2020-01-02 07:38:04.761 CET [1400] LOG:  could not rename temporary
statistics file "pg_stat_tmp/global.tmp" to "pg_stat_tmp/global.stat":
Permission denied
2020-01-02 07:44:15.785 CET [1400] LOG:  could not rename temporary
statistics file "pg_stat_tmp/global.tmp" to "pg_stat_tmp/global.stat":
Permission denied

I have checked the permissions of the folder and files, and I can not see
why this occurs.

best regards 
JF