How can I stop Confluence from crashing when viewing an Excel file?
Purpose
Confluence can sometimes have trouble rendering certain Excel files. The effects can range from the page being slow to load, not render at all, or for the entire site to become unresponsive and need to be rebooted.
You'll generally see entries like this in either the catalina.out or atlassian-confluence.log:
at java.lang.Thread.run(Unknown Source)
UIDefaults.getUI() failed: no ComponentUI class for: com.jxcell.HB[,0,0,0x0,invalid,alignmentX=0.0,alignmentY=0.0,border=,flags=4194304,maximumSize=,minimumSize=,preferredSize=,blockIncrement=10,orientation=VERTICAL,unitIncrement=1] java.lang.Error
at javax.swing.UIDefaults.getUIError(Unknown Source)
at javax.swing.MultiUIDefaults.getUIError(Unknown Source)
at javax.swing.UIDefaults.getUI(Unknown Source)
at javax.swing.UIManager.getUI(Unknown Source)
at javax.swing.JScrollBar.updateUI(Unknown Source)
at javax.swing.JScrollBar.<init>(Unknown Source)
at javax.swing.JScrollBar.<init>(Unknown Source)
at com.jxcell.HB.<init>(EYFN)
at com.jxcell.Adapter_2_0.createScrollbar(EYFN)
at com.jxcell.mvc.Viewview.<init>(EYFN)
at com.jxcell.ssView.<init>(EYFN)
at com.jxcell.View.append(EYFN)
at com.jxcell.View.<init>(EYFN)
at com.jxcell.View.<init>(EYFN)
at com.benryan.conversion.SpreadsheetConverter.convert(SpreadsheetConverter.java:476)
at com.benryan.conversion.XlsConverter$1.doConversion(XlsConverter.java:45)
at com.benryan.conversion.DocConverter.execute(DocConverter.java:61)
at com.benryan.conversion.macro.ConverterMacro.execute(ConverterMacro.java:250)Solution
While later versions of the Office Connector do make improvements, occasionally a file can still cause problems.
There's a few potential causes relating to Excel file content:
- Specific cell formatting
- Merged cells
- Too many sheets/empty cells
A good test is to try restricting the sheet and columns/rows that are displayed. If this doesn't help, try saving the format as .xls rather than .xlsx file; .xlsx files use a lot more system resources than standard .xls files and often this will resolve the problem. In later versions of Confluence, .xlsx files are restricted to 2mb.