I have got the same problem now. Also tried al the above. 

The same thing is happening to me right now. 

My problem disappeared the next day. There was a small patch update tho. I hope it's fixed asap for you!

Thank you for the update. Let's see how it goes. 

Ciao. It happened to me some weeks ago. Uninstall and install again the app worked for me

Thank you, Vincenzo. I already tried that several times and it hasn't worked so far.

​@Guimirex what error message do you see? Also, you mean that the Strava app crashes as soon as you try to open it (i.e. not later when using some of it’s features, such as starting recording and such), correct?

Besides of what ​@Vincenzo already suggested:

• Is your phone / Android fully updated? Install the latest updates - they may be fixing bugs in the operating system that may be causing apps instability. 
• Do you have enough free space in your phone’s storage? Apps sometimes crash when the storage is almost full (meaning you would need to delete some unnecessary videos and such)
• When did this start happening? Try remembering whether you’ve e.g. installed any new app prior to first seeing the error. There might be some kind of conflict. To confirm that theory, you could temporarily uninstall that new app, to see if Strava is working well after doing that.

Thank you very much for all your help. I just restarted my phone and the app is running fine now.