In Uganda EMB officials and staff are allowed to vote. However it happens that in practice most do not get a chance to vote due to being on duty immediately prior to polling and long after. It is not possible to vote since most will be up before polling and will be at duty stations that are different from their registered ares for voting. It is unlikely they ever get a chance to cast their vote. The net effect is that even if you they are permitted to vote by law, unless special arrangements are made, they will not be able to vote. special arrangements are susceptible to manipulation and I wouldn't recommend them.
I'm not going to add to the discussion on legal bars above: there are a few cases, as discussed. However, the facilitation of voting by electoral staff in practice is an important and much bigger issue. It is pretty well inevitable that some electoral staff will not be registered to vote in the polling district where they are serving, and indeed some administrative systems actually encourage this to promote independence of polling staff. (I think the case for this depends on context, as it may well be more important that locally based electoral staff are more likely to be able to detect attempts at fraud.) In addition, those engaged in higher level electoral management are unlikely to be able to take time out on polling day to vote in person.
If advance or absentee voting exists, inability to vote in person because of service as an electoral officer should be a qualifying ground for it. If it does not, there is a case for introducing it for electoral officials otherwise engaged on polling day. The same argument applies in relation to people who are engaged in providing election security.
