QObject::moveToThread: Current thread (0x55c07be39a60) is not the object's thread (0x55c07c164490). Cannot move to target thread (0x55c07be39a60)

[danmeng90]

Hello, Liu:

I am running your code on Ubuntu16.04, however, when I run python demo.py, the following two lines showed repeatedly:

QObject::moveToThread: Current thread (0x55c07be39a60) is not the object's thread (0x55c07c164490).
Cannot move to target thread (0x55c07be39a60)

Is it a normal phenomenon or there's something wrong with my operation? Thank you for your time.

                                                                                                                                 Dan Meng

[Yuliang-Liu]

Hi there:

I have tested the code on several computers, but the error didn't occur.
Could you show more details about the error logs?

[jungwon-choi]

I was able to fix this problem by installing new pyqt.

if you are using anaconda, just write down below:

$ conda install pyqt

[theRealSuperMario]

I was able to fix this problem by installing new pyqt.

if you are using anaconda, just write down below:

$ conda install pyqt

I can confirm that. A working combination seems to be opencv-python==4.1.0.25 and pyqt 5.9.2

[WaseemSabir]

opencv-python==4.1.0.25 is not available for anaconda environment on Ubuntu. the version opencv-python==4.3.0.36 and above pyqt version 5.9.2 works fine! solved the issue for me!

[schauppi]

I resolved this error by downgrading from opencv-python 4.5.1.48 to opencv-python 4.3.0.36 with PyQt5 5.15.2 installed.

[Nurullah1313]

Thank you very much thanks to @schauppi, I solved it

[mikechen66]

I was able to fix this problem by installing new pyqt.
if you are using anaconda, just write down below:
$ conda install pyqt

I can confirm that. A working combination seems to be opencv-python==4.1.0.25 and pyqt 5.9.2

It does not help me out. It has repeated the same error.

[YunfeiZHAO]

make be change cv2.waitKey(0) to cv2.waitKey(1) can solve your problem

[HosikChae]

I resolved this error by downgrading from opencv-python 4.5.1.48 to opencv-python 4.3.0.36 with PyQt5 5.15.2 installed.

python3.6, opencv-python==4.3.0.36, pyqt5==5.15.2 worked for me.
(opencv-python==4.3.0.38 and all above didn't work)

[CharlesNord]

Python3.8, ubuntu 18.04.1 ,

pip install opencv-python==4.2.0.32

solves my problem

[daigz1224]

Python 3.8, Ubuntu 18.04, Conda Environment,
I resolved this error by removing opencv-python installed by pip, and use opencv installed by conda instead.

[ykn96]

I am unable to downgrade my opencv, what options do I have ?

ERROR: Could not find a version that satisfies the requirement opencv-python==4.2.0.32
ERROR: No matching distribution found for opencv-python==4.2.0.32

and

ERROR: Could not find a version that satisfies the requirement 4.3.0.36
ERROR: No matching distribution found for 4.3.0.36

[itsbvk]

I am unable to downgrade my opencv, what options do I have ?

ERROR: Could not find a version that satisfies the requirement opencv-python==4.2.0.32
ERROR: No matching distribution found for opencv-python==4.2.0.32

and

ERROR: Could not find a version that satisfies the requirement 4.3.0.36
ERROR: No matching distribution found for 4.3.0.36

@fatbringer 4.3.0.36 is compatible for only certain python versions. Check your python version against the available builds.. https://pypi.org/project/opencv-python/4.3.0.36/