[求助]coverage生成tin时的问题

<P>由linecoverage和pointcoverage共同生成tin时，添加line coverage过程中Weed tolerance为系统默认的0.7935，
向导各部过程选择如下："Choose a Z-value item"为CONTOURVAL（存有高程值的Item）；"Choose a surface type keyword"为Mass（默认情况）;下一步为默认。
按同样设置添加point coverage。最后转tin时却出现错误！
出错信息为：
Copyright (C) 1982-2002 Environmental Systems Research Institute, Inc.
All rights reserved.
CREATETIN 8.3 (Wed Dec 18 08:17:08 PST 2002)

Createtin: COVER D:\地形线生成dem\地形线coverage\linecov Line CONTOURVAL Mass # # .7935
Createtin: COVER D:\地形线生成dem\地形线coverage\pointcov Point CONTOURVAL Mass # # .7925
Createtin: END
Weed tolerance set to 0.793...
Loading arcs from coverage D:\地形线生成dem\地形线coverage\linecov...
Weed tolerance 0.793, input arc points 3928,  remaining 3885...
Loading points from coverage D:\地形线生成dem\地形线coverage\pointcov...
Proximal tolerance set to INFINITY...
Removing points within tolerance...
FATAL ERROR
Unable to access GRIDST (SERDUP).
Bailing out of BRKTIN

ODE sub-process failed
Arc: </P>

<P>请求哪位大侠能帮帮忙,小弟先谢过了!!</P>