[Koha] Export tool failure Koha 21.11.03.000

[Evan Stewart]

Hello,

I seem to be having a problem with the Export data tool (Tools > Export
Data).  When I click the Export link, I get a "503 Service Unavailable"
message.  All other tools I try are working fine. I'm running Koha on AWS
(see details below).

My local server versions of Koha (running on Debian) are working fine.
Just the AWS install is having the export tool failure.

Has anyone experienced this problem with exporting data?

Hosting Environment: AWS Lightsail, 2GB RAM
OS: Debian 10
Koha: 21.11.04.001
Server: Apache 2.4.38

Any thoughts on how to troubleshoot to discover the cause?

Thanks,
Evan Stewart