Report work fine on Development but error on VB build

[lovevthokie]

We are using RDC to run Crystal Reports with VB. The group Tree works fine on the development machine when the user clicks on the plus sign next to the name of the report. On the build that is on a clients machine, when the user clicks on the plus sign, they receive the error of "type Mismatch. The title on the error box is Crystal Report Viewer. The plus sign disappears and "Loading..." shows up under the name of the report that the user just clicked on. I must be missing a .dll in the build, but I can't seem to figure out what I might be missing! I have checked everywhere on what I should include and as far as I can tell, everything is there. Right now I have disabled the group tree, but obviously that won't work since the user can choose more then one report and some reports have groupings.

Thanks in advance for any helpful ideas!