Symptom

When trying to load BarTender Print Portal (BPP), you receive Error 500.0 which points to the following dll file:

Environment

• BarTender Print Portal 

• BarTender 2016 and above

Solution

This isn't a BarTender error as much as it is an IIS setting. When a request to load a web page happens, IIS loops through a list of ISAPI filters, which is pretty much a list of dll files. It attempts to load any dll files on this list until IIS finds what it needs.

This problem is caused when one of the filters is a 32-bit DLL on a 64-bit OS. Since BarTender must match the bitrate of the operating system when running BPP, this causes a bitrate conflict.

To find the potential conflict, please do the following:

1. Open the IIS Manager
2. Expand the sites then click the site where BPP is hosted. By default this is "Default Web Site"
3. Click ISAPI filters (located in the IIS section)
4. Look for the filter address that matches the message in the web browser

The only filters BPP uses are the two ASP.Net filters, neither of which will cause the ISAPI filter error.

If the offending filters cannot be removed (as other sites in IIS depend upon them), consider moving BPP to its own site. You can host multiple sites in IIS

The two sites here can be run on different IP addresses, host names, or ports. We do not recommend which to run these on as that's outside the scope of our recommendations.

Important note: check the ISAPI filters of the new site before launching the new BPP. IIS copies the default settings of the Default Web Site so the offending filters may carry over

Additional resources

Please refer to ISAPI Filter Overview from Microsoft for more information.