you are presumably in two column, and as the error says, that isn't supported by longtable. You could put \onecolumn before the table
– David CarlisleOct 28 '19 at 11:36
@DavidCarlisle Please can you elaborate on this? The document i am writing is two column/page.
– CutieOct 28 '19 at 12:09
you need to not use longtable (eg use xtab instead) or you need to switch to \onecolumn for the table and \twocolumn again afterwards.
– David CarlisleOct 28 '19 at 12:28
But my table is long as well as will have to be in landscape position because of the content
– CutieOct 28 '19 at 12:30
1
xtab does multi-page tables, but if the table is so wide that you need it landscae then you persumably want to switch to one column for the table, otherwise you have to squessze it in to half the width, also the lscape package also only works in single column.
– David CarlisleOct 28 '19 at 12:33
Thank you very much @DavidCarlisle your intervention. It's of great help. I'm sorted!
– CutieOct 28 '19 at 16:47
\onecolumnbefore the table – David Carlisle Oct 28 '19 at 11:36\onecolumnfor the table and\twocolumnagain afterwards. – David Carlisle Oct 28 '19 at 12:28