Error: dropped because of all positive or all negative outcomes.

[Sakshi Rajatbhai Tewari]

Hello all- happy pi day! Here is my data example:

* Example generated by -dataex-. For more info, type help dataex
clear
input float(fauxid pt_type2) int matchid byte c_everhpvcanc
 502.2293 0 46 0
 373.8853 1 46 0
 386.9427 0 46 0
 423.8853 1 47 0
 515.9236 0 47 0
 435.0319 0 47 0
 498.7261 0 48 0
550.63696 0 48 0
 478.6624 1 48 0
 452.2293 0 49 0
 528.6624 0 49 0
607.00635 1 49 0
 470.0637 0 49 0
593.94904 0 50 0
 521.0191 0 50 0
 448.7261 1 50 0
 390.7643 0 50 0
 467.8344 0 51 0
 560.1911 0 51 0
 452.5478 1 51 0
 574.5223 0 51 0
 464.3312 0 52 0
 557.6433 1 52 0
 375.4777 0 52 0
516.87897 0 52 0
438.21655 0 53 0
 629.2994 0 53 0
 404.7771 1 53 0
 375.7962 0 53 0
 505.7325 0 54 0
 588.8535 0 54 0
598.40765 1 54 0
 462.1019 0 54 0
 534.0764 0 55 0
 516.5605 0 55 0
 323.8853 1 55 0
532.80255 0 55 0
 499.6815 0 56 0
 442.3567 0 56 0
 423.5669 1 56 0
 581.8471 0 56 0
 454.7771 1 57 0
514.96814 0 57 0
 604.4586 0 58 0
  406.051 1 58 0
514.33124 0 58 0
 596.4968 0 58 0
556.05096 0 59 0
528.34393 0 59 0
 437.8981 0 59 0
 471.9745 1 59 0
 479.6178 1 60 0
528.02545 0 60 0
551.59235 0 60 0
 619.7452 0 61 0
 440.4459 1 61 0
 354.1401 0 61 0
 429.9363 0 61 0
472.61145 0 62 0
 556.6879 0 62 0
 409.5541 1 62 0
551.27386 0 62 0
 421.0191 1 63 0
 476.4331 0 63 0
537.26117 0 63 0
527.38855 0 63 0
 541.7197 0 64 0
 432.1656 0 64 0
 431.2102 1 64 0
 526.1146 0 64 0
 500.3185 0 65 0
 378.6624 1 65 0
 495.2229 0 65 0
587.26117 0 65 0
411.78345 1 66 0
 584.0764 0 66 0
 468.7898 0 66 0
382.80255 0 66 0
 332.4841 1 67 0
 561.1465 0 67 0
 448.0892 0 67 0
 519.1083 0 67 0
 574.2038 0 68 0
 499.0446 0 68 0
598.72614 1 68 0
 631.2102 0 68 0
 552.5478 0 69 0
  377.707 1 69 0
583.75793 0 69 0
 608.2803 0 69 0
 362.1019 0 70 0
  460.828 1 70 0
 609.8726 0 70 0
 630.5732 0 70 0
 341.4013 1 71 0
  493.949 0 71 0
 445.5414 0 71 0
 344.2675 0 71 0
 508.9172 0 72 0
 553.1847 0 72 0
end
label values pt_type2 pt_type2l
label def pt_type2l 0 "0-control", modify
label def pt_type2l 1 "1-case", modify
label values c_everhpvcanc EVERHPVCANC_FORMAT
label def EVERHPVCANC_FORMAT 0 "0-No", modify

Fauxid is a fake ID variable, pt_type2 is the case control status variable, c_everhpvcanc is indicator for ever having hpv cancer, matchid is the matching id for cases and controls.
There are 2 everhpvcancer=1 people, 1 case and 1 control (not shown in this data example)

when i run clogit.

clogit pt_type2 c_everhpvcanc, group(matchid)  or

I get no estimate (".")
But i cant seem to see why this might be happening when i look at the dataset