I do not know how it happend but i got one log record with empty call sign field
This was reported by TQSL when trying to upload my log to LOTW

N1MM can not remove a record with empty call field i found out.
Deleting that record is normally confirmed by N1MM
But the faulty QSO record does not remove.
Here 3 PC's  in the network running N1MM  PC3 has IC706  + XVTR  23cm
PC2  is running WSJT / WSPR with the K3 or logging N1MM
PC1 the fastest Laptop is for contest use
All PC's have N1MM  and TQSL /LOTW
Deleting a QSO that is logged by an other PC in the network is not allowed that makes sense.
To delete that record I filled in a fantasy call DE1LET   and then it can be deleted for real.
You would think:
So what, let TQSL ignore the empty record,  just update it.
That's what i did
But  when checking in LOTW  QSO's where missing just after the "empty"field
 that happened to be my season best DX of course
among  6m   several JA
50 MHz  DS4EOI      2017-06-08   9:18   New DXCC Korea 1rst time in 30 years 6m QRV        
50 MHz  WA6OSX   2017-06-08  17:49  JT65  CM97

Real rare DX from JO33hg  is a one time per season event if it ever happens.
After that good DX day June 8   many DX-less days followed with 1x hop es
I see some 200 km south of me reporting USA midwest  Caribean VK6 VK4 OA PY 9Y XE
I knew from the past JO33hg is not 6m DX wonderland so nothing new,
Okay the 5 ele here will not bring a full 10dBd , possible 6dBd if it is real bad but it isn't .
Extending the 5m boom  to 9m  with 2 elements would that really make  the difference?
I doubt that very much
A beam up with little more "gain" it will not harm.
But driving to Italy with a dipole would bring more result.

ok....  LOTW continue
On PC 3  the TQSL certificate was already expired.
So it seems wise to renew the certificate at this PC-1 before it expires
I updated  from the requested LOTW tq6
Then backup and restore to the 2nd and 3 PC
al certificate  had  gold certificate label again
It looked all okay.
But next day this PC1 was suddenly out of business for uploading LOTW

The LOTW certificate ID did not match to any of my the 3 PC's
The best way is to set up 1 PC working for LOTW upload and then copy the working configuration to the other PC  by backup and  restore on the other  PC's  using the working backup file.

After 2 times deleting and new request for  TQ6
LOTW  did work again  on PC1,  then copied the configuration to the other 2 PC's and fixed.
Finally the missing QSO's  are in LOTW after forcing to process uploading identical QSO
The N1MM log synchronise  a lot better in the latest versions, but still my general logs ar not identical on the 3 networked PC's