I have the router with versions 5.26 and I can not update for any other version. I bought the license level 5. it only asks to update to version 6.37.1 but the error in the middle of the download and even copying the file to the files folder and restarting does not update and the file continues in the folder. I do not know what else to do.

copying the file to the files folder and restarting does not update and the file continues in the folder.

What's in the log after restart?