Hi Cynthia,
You may want to see how large the this response is. In the past, I have seen problems with invalid characters in this, but that does not sound like your problem.
https://yourserver/dhis-web-dataentry/getMetaData.action
You will of course need to change yourserver to which ever server you are accessing.
If there are a large number of organisation units, many datasets or complex data entry forms, this payload may be very large. This might help to explain why it takes so long, particular if users might have a slow connection.
Regards,
Jason