It is a bit difficult to help without having the possibility to reproduce your issue, however here are a bunch of things that may be worth considering:

There was a known problem in a previous version of SAS regarding this (you can read more about it at http://support.sas.com/kb/13/510.html). You may try to remove the REF= options (or use REF=FIRST or LAST) and to see if the issue persists (i.e., you could try to run the code below)

proc surveylogistic data=nhis29;
cluster ppsu;
strata pstrat;
weight wtfa;
class SRVY_YR edu pov sex / param=ref ref = FIRST;
model ft(event='1') = srvy_yr edu pov sex / expb;
run;

If this is still not working, I would suggest to start from the simpler model which is working, and to add variables one at a time, so that you can understand when the error appears and hopefully gather more information about the reason (which, as PBulls suggested, may be related to the combinations of parameters you are considering in the data).

I would also maybe try to temporarily remove the cluster and strata statements to see if the full model runs without those:

proc surveylogistic data=nhis29;
weight wtfa;
class SRVY_YR edu pov sex / param=ref ref = FIRST;
model ft(event='1') = srvy_yr edu pov sex / expb;
run;