My drawing was refused as too large.

AutoMEP reads the whole drawing when it plans, so a very large file can exceed what it can hold in one pass. Recent work cut that payload down considerably and many drawings that used to be refused now run, so if you hit this a while ago it is worth trying again. If it still happens, splitting the file helps and rewording the request does not: one floor or one area per file is the split that works, because the whole drawing is read either way. Your usage is returned whenever a job is refused for size.