Scheduled report PDFs rendered blank/grey when IncidentInvestigation module is enabled (Zabbix 7.4.x)

[MiroV89]

Hello,

I have identified an issue between the IncidentInvestigation module and Zabbix Scheduled Reports.

Environment:

• Zabbix Server 7.4.10
• Zabbix Web 7.4.10
• Zabbix Web Service 7.4.10
• PostgreSQL 16 + TimescaleDB 2.15.3
• Chromium used by zabbix-web-service
• IncidentInvestigation module enabled

Problem:

When the IncidentInvestigation module is enabled, Scheduled Reports generate an almost empty PDF (grey/blank pages).

The report email is sent successfully but the generated PDF content is missing.

What I observed:

• Scheduled Reports stop working only when IncidentInvestigation is enabled.
• The issue affects even a brand-new dashboard containing only a Clock widget.
• Creating a new user does not solve the issue.
• Creating a new report does not solve the issue.
• Recreating dashboards does not solve the issue.
• Upgrading from Zabbix 7.4.3 to 7.4.10 does not solve the issue.
• Replacing zabbix-web-service versions does not solve the issue.

Troubleshooting performed:

• Created a completely new Zabbix installation with a fresh database.
• Scheduled Reports worked correctly.
• Compared database contents and configuration.
• Eventually identified the IncidentInvestigation module as the root cause.

Resolution:
After removing/disabling the IncidentInvestigation module, Scheduled Reports started working immediately and PDFs were generated correctly.

Possible cause:
The module appears to inject JavaScript globally. It may be affecting pages rendered through the Zabbix print/report mode (dashboard.print) used by zabbix-web-service and Chromium.

Thank you.

[Supernova1961]

We are experiencing the same problem with Zabbix 7.0.25.

Environment:

Zabbix Server 7.0.25
Zabbix Web 7.0.25
Zabbix Web Service 7.0.25
PostgreSQL 16 + TimescaleDB 2.15.3
Chromium used by zabbix-web-service
IncidentInvestigation module enabled

[CE-RS42]

Same problem here with several 7.0.x versions. We are running in K8s.

[CE-RS42]

Root cause + fix confirmation

This was caused by the module's global stylesheet assets/css/blue-theme.css shipping an unscoped rule:

@media print { body * { visibility: hidden; } }

Since module assets load on every page and zabbix-web-service renders dashboards in print media, this hid every element on every scheduled-report render → blank PDFs (page layout intact, nothing painted).

This is already fixed on main: commit b3234e9 removed the print block (along with the Export report button).

For anyone on an older pinned release — or who wants to keep the Export report feature — scoping the rule instead also fixes it:

body:where(:has(.mnz-incident-investigation-wrapper)) * { visibility: hidden; }

A variant with this fix plus print-layout improvements (pagination, fit-to-page) is available here: https://github.com/CE-RS42/IncidentInvestigation/tree/conclusion-enablement-print-fixes

Suggest this issue can be closed.