Bug - issues and problem - Unity

Suppose, when you want create your own lighting in unity editor . then you need to do some settings based on scenes.  if you imported some 3D Assetes from any other 3D creation software (ex. I am using Blender ) and then you need to generate lightmap UV to the respective model. when you do it and you got message like "Hold On" . it will take more time or maybe freeze your pc . In this case you need to understand that your imported model have high polygons and you must minimize the polygons without changing the model structure. In blender, already have a decimate option but in some case that will not work. so then you need to install an external software called " MeshLab ". you click on meshlab and download it. Now, i am going to give you one youtube link that will show you how to decimate the high poly model to low poly. In this video, you need to change one thing in quadric edge collapse decimation. you must check preserve boundry of the mesh tha

you have installed unity hub in your pc and unity hub sign in process is not working but you have  previous version of unity ID. when you are new then don't worry it will work fine . but if you have any old version of unity then you have to follow the following tips:  1.  you have to uninstall the previous version of unity from your pc. only if you have option in unity hub  but don't uninstall it  manually . because some unity hub application not showing uninstall option. like this...... my recommendation is to go manual installation of unity and you get higher version as well when you follow the below link.. https://unity3d.com/unity/whats-new/2019.3.9 this link will provide you higher version of unity that are not present in unity hub. any information is wrong in my post let me know in comment section...please....

  ***** 3 ways to solve this problem **** 1. w hen you are using "unity version" below "unity 2019.3.0" then you must follow the following path.       open unity editor → File → Build settings → player settings → other settings→                configuration → "scripting runtime version → .Net 3.5 equavalent" (←select it). 2.   w hen you are using "unity version" > "unity 2019.3.0" then you open the visual studio installer .       I hope, you installed the visual studio community if yes, you click on modify option button       then you install the .Net desktop development and restart pc.               this works definitely in any version of unity... 3.  when above two cases are not working then your pc current location change to  "United States"       Control panel→ Region→Location.     I hope this will solve your problem but when nothing happen by using these cases. then you  specify your probl