Hey so I don't know if this is the right place to ask but has anone ever had the same issue i am having? I installed the newest Mechjeb file and installed it correctly. The parts show up, I can put them on my ships but they don't do anything, I never get the toolbar/window on the side of the screen. My KSP is the newest version .90.75... I checked this all by having my brother walk me through the install on his computer. We have the same versions and performed the same steps side by side. The one thing I found was when i downloaded the file, for some unknown reason I didn't get the PluginData folder inside of the Plugins folder inside of Mechjebs folder. We did the download at the same time from the same link and he got the file but i didn't. I copied the file from his computer and brought it into mine, still no fix, parts show up, can be attached, but no functionality. At this point we thought maybe it was my copy of KSP itself so we tried a complete game copy. Copied his entire KSP game file onto thumb drive then brought it to my computer and still same problem. I have had similar issues with the mods: Chatterer, ATM, and every planetary editor I could find. I did not look into these others as closely because Mechjeb is more important to me. I do have the SpaceY Mod and it works perfectly. I am baffled at this point and could use any help at all. I have spent almost as many hours trying to find a fix for these problems as I have actually playing the game.