Hi there. Thanks for reporting this.
This sounds like a memory error. Your mention of "spinning" suggests that you're upgrading through the "Upgrades" panel in WordPress. Try upgrading through the Plugins menu instead, and you'll probably get a memory error ( or max execution error ) there, which will reveal the root cause of the issue.
= Why do I get memory errors during automatic upgrade? =This depends on your hosting provider and/or server configuration. Some web hosting companies impose very low limits on the amount of memory available to WordPress® during the execution of a single script. Since s2Member is a larger plugin, WordPress® may exceed conservative limits set forth by shared hosting companies. Don't feel bad, it's a very common problem. The solution is to upgrade manually. Memory limits only affect the WordPress® auto-installation/upgrade routine, not the actual functionality of WordPress® or s2Member.
Upgrading manually:
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