College students can't sign the recruiter's signature online.

There are four reasons why college students can't sign recruiters online:

1. Signature picture size exceeds the limit: if the signature picture size exceeds the limit, the signature will not be uploaded or saved.

2. Browser or system problems: Some browsers or operating systems may have compatibility problems, which makes it impossible to upload or save signed pictures normally.

3. Network connection problem: Sometimes the network connection is unstable or the network speed is too slow, which may also cause the signature to be unable to upload or save.

4. Signature making problems: If there are problems with the signature itself, such as low resolution and poor quality, the signature may not be uploaded or saved.