I would like to share an issue i had recently around this error : "Error loading USE or USELSX module' 

I searched the internet to find a solution but all the solutions out there did not help me at all.

I have a database with more than 50 script libraries all interlocked according whats called. This worked quite fine in my development enviroment and my qa enviroment until it got to our production enviroment.

What would happen is that the code would run on the server and then when it called a specific function it would crash with "Error loading USE or USELSX module" . If i bypassed the function it would go until the end but naturally not actually do what it needs to do. I created a new function in the library that had my calling function and called that, without calling anything else and that did not work either. 

I even took the library been called added it to an agent, called the agent from my main script (to segregate) the code and that failed to. So it look like it was the library been called yet the code was exactly the same as in my dev and qa enviroments. To make matters worse the prod server is part of a cluster and the failover server in that cluster worked fine. 

I asked admin to double check the servers cause I had a feeling that something must be different there and they told me all was the same.

Let me just say our prod enviroments security is insanely strict. Both servers in the prod have to have the same security. This would be at a Domino level and at a windows level. Our servers are both started up under a specific user which has restricted rights to the file system.

So my problem was actually very simple to resolve.

I managed to work out that when a specific path was set on the file system, the running windows user did not have the correct rights to the file system and thereby threw "Error loading USE or USELSX module".  What it was actually doing was to try and create a directory that was missing. On my fail over server the admin had manually created the directory. The code I have in checks for the directory and then creates it if its missing. The thing is that I had no error trapping at this point in the code so battled to work out exactly where the problem was.

 

Hope this can help others

 

thanks