In the beginning I had the same problems with error messages. And I was wondering...I did everything as in the guide, so I was going to manually take care of the errors inside the code *;D* ... and I did well, but during gameplay I had TvT error and server crashed all the time :o, even if eclipse compiler told me something different that there is no error inside the code!
Finally I found out that using 3.7 eclipse isn't enough (I don't know why)...but while reading on L2java forum I found out that they used a eclipse beta build.
After I reinstalled that bete eclipse whatever - I didn't had compile errors but therefore I couldn't see progress status bar, so I had to wait some time without noticing if the Server+Datapack.rar's where build or not, but they where.
That's at least my strange story.