Hi,
This shape mean that isometric drafting settings is on . you can get it back normal from ISODRAFT command >> Orthographic option . OR from the status bar as shown below .
![khgjkhjk.png khgjkhjk.png](https://forums.autodesk.com/t5/image/serverpage/image-id/498799iCD9CAEBFFC0AB949/image-size/large?v=v2&px=999)
Command: ISODRAFT
Enter an option [Orthographic/isoplane Left/isoplane Top/isoplane Right] <isoplane Top>:o