E910_TR9.1.4.3 GridCacheException Error During Grid Export to Excel or CSV

Hi, I have tested the standard P4210 sale inquiry exporting data into excel..It worked but as for this custom object P564211I, it would constantly give error web client exception error ..pls refer attached

Whenever i click on end page,,and go to export , the error would happen ...If i click on certain page of records, it would not show the error....

13 Mar 2015 16:12:50,945 [SEVERE]  - [RUNTIME]         exception in processEvent com.jdedwards.runtime.base.GridCacheException: com.jdedwards.runtime.base.GridCacheException: A manual deletion of disk cache files may have occured.

13 Mar 2015 16:12:50,945 [SEVERE]  - [RUNTIME]         An exception has been caught by the Web client. Please contact your system administrator. See log for details. Exception id =Exception_2015-03-13 16:12:50.945_JDE   com.jdedwards.runtime.base.GridCacheException: A manual deletion of disk cache files may have occured. com.jdedwards.runtime.base.GridCacheException: com.jdedwards.runtime.base.GridCacheException: A manual deletion of disk cache files may have occured.