Can't log into Magento Admin, "Invalid Captcha" error appears

[coatesjonathan]

Summary

I cannot login to Magento admin, I just get this response every time, when I initially entered my login details, there was no captcha there, it appears after I try to login.

Then once I've tried again, using the captcha, I get this error:

Any help would be appreciated?

[magento-engcom-team]

Hi @coatesjonathan. Thank you for your report.
To help us process this issue please make sure that you provided the following information:

• Summary of the issue
• Information on your environment
• Steps to reproduce
• Expected and actual results

Please make sure that the issue is reproducible on the vanilla Magento instance following Steps to reproduce. To deploy vanilla Magento instance on our environment, please, add a comment to the issue:

@magento-engcom-team give me {$VERSION} instance

where {$VERSION} is version tags (starting from 2.2.0+) or develop branches (2.2-develop +).
For more details, please, review the Magento Contributor Assistant documentation.

@coatesjonathan do you confirm that you was able to reproduce the issue on vanilla Magento instance following steps to reproduce?

• yes
• no

@coatesjonathan, please refer to the Community Forums or the Magento Stack Exchange site for advice or general discussion about this issue. The GitHub issue tracker is intended for Magento Core technical issues only.