FRM-40900: Unable to allocate record buffer. Clear form to continue.
Cause: Failed attempt to allocate memory for a fetched or new record. The remaining records that are queried are temporarily buffered on disk. This is an indication that no more temporary files can be written to the disk.
Action: Clear form and then attempt to continue. You may have to exit the form and then re-open. Also, make sure there is enough disk space and that you have write privileges to the disk drive and directory.
Exit that form and try delete your temporary file then try open the same form.