Allowed memory size of xxxxxxx bytes exhausted
Thie error indicates that your PHP process on your server ran out of memory. When PHP is run, a certain amount of memory is reserved for your use and if a script tries to use more memory than is available you can run into problems. A standard PHP installation is set up to have 8MB of memory available for use, but depending on your Host or server admin, you may have more or less memory available.
ExpressionEngine will generally run fine on 8MB of memory. Some processes such as data importing, Moblog email checking, file uploading, image thumbnail generation, and similar can require larger amounts of memory when they are run.
If you run into a problem such as:
Allowed memory size of 4194304 bytes exhausted
that means that you have run out of memory for PHP. In the above case, only 4MB are available to PHP, which is far less memory than typical. If you consistently run into these memory limits then you need to contact your Host/server admin and see about having your limit increased.
