The version of 1. system is incompatible: corresponding drivers and components are required for electronic signature. If your mobile phone system version is too low or incompatible with the APP version, it may lead to a black screen problem. At this time, you can try to update the mobile phone system, or uninstall and reinstall the APP to see if it can solve the problem.

2. Telephone APPlication conflict: On some mobile phones, there may be a conflict between the telephone application and the Jiangsu market supervision app, resulting in a black screen problem. At this time, you can try to close the mobile phone application and try the electronic signature function again.

3.APP permission setting: Jiangsu market supervision app needs access to camera, storage and other permissions to operate normally. If you don't authorize the relevant permissions during use, there may be a black screen problem. At this time, you can open the phone settings to see if you have authorized the relevant permissions of the APP.

4. Network problem: If your network connection is unstable or slow, the electronic signature function may not work properly. At this time, you can try to switch networks or check network connections to see if you can solve the problem.