Hi,
Thanks for your answer. Compiling for 64bit didn’t make any difference – but probably the problem is not in OpenXmlPowerTools after all.
I made a small test app, just performing the merge. It completes fine (although it takes more than 30 minutes…) on the same server where the actual “serious” application crashes, and it allocates a lot of RAM (~7GB) for the merge process.
The actual application is a server application, running standalone (OWIN) as a Windows service. The 2GB limit is probably enforced by some of the surrounding infrastructure, I am struggling to find out where.