XML Document Takes a Long Time to Open
Problem
Oxygen XML Author takes a long time to open an XML document.
Cause
It takes longer to open an XML document if the whole content of your document is on a single line or if the document size is very large.
Solution
If the content is on a single line, you can speed up loading by selecting the Format and indent the document on open option (in the Format preferences page).
If the document is very large (above 30 MB), make sure that the value of the Optimize loading in the Text edit mode for files over option (in the Open preferences page) is greater than the size of your document.
If that fails and you get an Out Of Memory error (OutOfMemoryError) you can increase the memory available to Oxygen XML Author.