When you load an information link on Web Player, you see entries for ID1 and ID2 to be "null" in your action log database. See the log entry below with "Null" values,
 

LOGGED_TIME	USER_NAME	LOG_CATEGORY	LOG_ACTION	SUCCESS	ID1	ID2	ARG1
2017-10-06 18:03:25.160	sfadmin	info_link	load_il	1	NULL	NULL	f3b70efe-9c5a-477e-b9f1-191858e7e766

This might happen when you open information links with prompts or on-demand information links or if you have any errors while opening the information link. However, if the information link is executed successfully, you would also encounter a log entry with successful data for  ID1 and ID2 values. For example look at the log entries below for when the information link "SUTestLink" (which had 3 prompts) is executed:
 

LOGGED_TIME	USER_NAME	LOG_CATEGORY	LOG_ACTION	SUCCESS	ID1	ID2	ARG1
2017-10-06 18:03:25.160	sfadmin	info_link	load_il	1	NULL	NULL	f3b70efe-9c5a-477e-b9f1-191858e7e766
2017-10-06 18:03:25.160	sfadmin	info_link	load_il	1	NULL	NULL	0933d4e7-7a98-4e20-a97a-f0549649a455
2017-10-06 18:03:25.160	sfadmin	info_link	load_il	1	NULL	NULL	b03fb240-d0ce-46e4-b52b-9fc0ff30f548
2017-10-06 18:03:25.160	sfadmin	info_link	load_il	1	812137b5-f008-4cb5-89c4-d08694e59661	/TestData/SUTestLink	a3098ff1-2a53-4203-8901-e6d598939359

You can see three entries with empty values ID1 and ID2 as the information link had three prompts in it. 

This article describes why empty values are found in ID1 and ID2 columns for 'load_il' log actions in the Action Logs

Doc: Action Log entries:

• https://docs.tibco.com/pub/spotfire_server/7.11.0/doc/html/TIB_sfire_server_tsas_admin_help/GUID-67B1DBFC-B1DB-49B1-A492-4B684FAADB72.html