You can find server logs at different locations.

Spotfire Server logs

Spotfire Server logs are located under <installation dir>\tomcat\logs folder.

Example: C:\spotfire\spotfireserver\<version>\tomcat\logs

Spotfire Server Upgrade logs

Spotfire Server Upgrade logs are located under <installation dir>\tools\upgrade\logs folder.

Example: C:\spotfire\spotfireserver\<version>\tools\upgrade\logs

To change these default locations, see Changing the default location of server logs.