If you install an extension and the assembly version is newer than the one used in the base app, if you run Repair-NavApp, the base application captures the newest version and applies that. In our case, that ended up breaking the Export in Excel function that uses Assembly version 2.9 by default, and by installing an extension and repairing after an upgrade of the environment, the version was upgraded to 2.11. It took us a lot of manual labor to finally notice the difference in the versions in C#. Shouldn't there be a check in the base app to check the Assembly version? If the environment is not flexible for version changes, at least a better error message than "The type of one or more arguments does not match the method."