Solved for me as well this morning. had two un synced activities from two days ago that synced today strait away with no issues. 

Same issue on galaxy watch 5 and s23....

Same issue here on the galaxy watch..

Nope still not sorted . Did a run today and didn't load.

Any resolution on this? Just got the error today

Same issue here on the galaxy watch 4

Same issue here as of Apr 6 on galaxy watch 6

Where will we find an update on this?

Had the same issue today.

Same issue here on galaxy watch 4:( Strava, need a fix!!

Same issue with Pixel watch and I need to upload run for a virtual 5k. 

Had the same problem with my pixel watch. Took like 6 hours to finally upload. No rhyme or reason, just kept clicking the sync on my watch.

This has been happening to me since last weekend.  Sometimes it will magically sync, but it's very infuriating as we are paying for this app.  I have a Galaxy 6 watch and Samsung S23.  

Same issue, s23 and galaxy watch 5

Any update yet?

This just happened to me today.  Samsung Galaxy Watch 4 paired with Sony Xperia 1 ii.

My issue resolved after a few hours of additional updates and rebooting.

It just happened. Galaxy Watch 5 Pro with Galasxy S22. It wont sync and says "Parameter specified a non-null is null: method m9.e.apply, parameter apiErrors". 

Same issue today, Pixel Watch 2. Please post a solution soon!

Same here. Happened before and later in the day it magically synced.

Same error on watch 4 + A54

I did a run on Thursday evening, it did not sync untill friday morning, and I kept receiving the parameter... message.

Today I did another run, once again it won't sync, even after rebooting my phone and my watch.

Any news on this? Pixel watch got the error now 

Same issue on my Tikwatch 3 Pro Ultra GPS. This issue persist after last update i think. WearOS 3.5.

" Parameter specified as non-null is null: method ub.d,apply, parameter apiErrors"

Same issue.  Galaxy watch 5 pro.  Samsung S20.

Having the same problem, which is frustrating when I'm training. I have a Samsung watch and a pixel phone, I've restarted both several times and waited a few hours. Has anyone found a fix yet?