Unable to allocate sufficient memory ....

Hello,

I'm Hyesook Sung. I'm Korean.

I use GUPTA tool(SQL Windows).

I recently found SQL errors. sometimes....

' Unable to allocate sufficient memory '.
My Server Memory is 512MB.

sp_configure is

name minimum maximum config_value
.....
database size 1 10000 2
....
locks 5000 2147483647 20000
longwrite sleep -1 500 0
....
max worker threads 10 1024 255
media retention 0 365 0
memory 2800 1048576 150000
....
network packet size 512 32767 4096
....
RA worker threads 0 255 3

I would appreciate any advice, inspiration, and guidence?

Kindest regards, EA