Question: I have SDK version 25, when i import a project in android studio this error occurs. 

> 
> "Install missing platform(s) and sync project".
> 
> 
> 

If I click this link, I get another error, which says:

> 
> "The following packages are not available: - Package id
>  platforms;android-23".
> 
> 
> 

[sdk error](https://i.stack.imgur.com/hY1P2.png) 

[my SDK version](https://i.stack.imgur.com/8e89N.png)

Answer: 
This error occurs in higher versions of openCv like 4.3.0.38 or higher, i tried 4.3.0.36 version with pip and this problem solved for me, but in lower version i were facing lots of problems, like window not loading correctly,If are using Ubuntu i would recommend you to uninstall opencv from your system completely and try to reinstall with command given below,

```
pip install opencv-contrib-python3

```
I had the same problem. Using opencv imshow function raised the moving thread error. Eventually, I found that Ubuntu 16.04 has a preinstalled pyqt5 while OpenCV needs pqty4.
Therefore, this may be caused by conflicting installations of Qt libraries. The following command fixed it for me:

```
sudo apt-get remove libqt5x11extras5 libqt5x11extras5-dev

```