Item 1: Start TurboCAD in Administrator Mode. If you have installed TurboCAD so that its icon is on the Windows Backdrop, then place the cursor over it and right-click to select Administrator Mode from the popup menu. The next easiest method is to tap the Windows Start button and type "TurboCAD" (do not hit the <Enter> key), then place the cursor over it and right-click as in the 2nd sentence.
Now, when you see the Server Error, click the "Don't show again" radio button at the bottom left and continue. Now that you have done this once in Administrator Mode, you don't have to do it again until you re-install TurboCAD.
Item 2: I've never seen this malfunction before. Three solutions come to mind.
a) Start a new file and see if the problem occurs here, too. If so, then make everything visible in the file with the problem, select Wireframe mode, Select All, Copy, then Paste into the new file (also in Wireframe mode).
b) Position the cursor in a blank area of the TurboCAD window that is outside the Model or Paper space area. Right-click and select the Options tab at the top left of the popup menu, then click on the Load From: button (making sure that your preferred Workspace is listed below it). To exit this popup, click on Close.
c) Open Windows Uninstall a program, single-click on the TurboCAD program listing in the program listing, then click on Repair command just above the program listing.
TC Pro Platinum 2018, 2017, 2016 & 2015 (all with LightWorks & RedSDK) & V21
System: i7-5820K @ 3.30GHz, ASRock X99 Extreme4, 16GB DDR4-2133 RAM, Gigabyte GTX 970, Samsung NVMe SSD 950 (256GB), Windows 7 Pro (64-bit) SP1