出现这种问题，
①首先检查用户对应的角色名，然后看路径设置是否正确，有没有相关的权限，如果这些都没问题，然后就尝试下面的操作：
②重起FTP服务，最好从服务里面重启(不能根本解决)；
③重新设置Server-U帐号和目录访问里的文件路径(如果还不行，尝试下面操作)；
④删除用户，重新建。
原创 SU整理（FTP)收藏
整理如下：
1开头-成功
2开头-成功
3开头-权限问题
4开头-文件问题
5开头-服务器问题
150 FILE: %s
150 Opening %s mode data connection for %s (%I64d Bytes).
150 Opening %s mode data connection for %s.
150 Opening ASCII mode data connection for /bin/ls.
150 Opening BINARY mode data connection for MLSD.
200 (end of 'index %s')
200 Command channel switched to clear-text.
200 Command OK, %I64d Bytes available on %s
200 Command okay.
200 EXEC command successful (TID=%u).
200 Message received okay.
200 MLST OPTS
200 MODE S ok.
200 MODE Z LEVEL set to %d.
200 MODE Z ok.
200 Noted.
200 Opened OK (but not really).
200 PBSZ command OK. Protection buffer size set to 0.
200 PBSZ=0
200 PORT Command successful.
200 PROT command OK. Using clear data connection.
200 PROT command OK. Using private data connection.
200 SSCN:CLIENT METHOD
200 SSCN:SERVER METHOD
200 STRU F ok.
200 STRU R ok.
200 Transfer progress notification is off.
200 Transfer progress notification is on.
200 Type set to A.
200 Type set to I.
202 Command not implemented, superfluous at this site.
202 Command not implemented, superfluous at this site.
210 UTC%+ld
211 End
211 End of status.
211-Extension supported
211-Status for user %Name from %IP:
213 %I64d
213 %s
214 Direct comments or bugs to bugs@bugs.com.
214- The following commands are recognized (* => unimplemented).
215 UNIX Type: L8
220 Service ready for new user.
220 Serv-U FTP Server v%s for WinSock ready...
221 Goodbye!
226 ABOR command successful.
226 Transfer complete.
226 Transfer complete.
226 Transfer complete.
227 Entering Passive Mode (%d,%d,%d,%d,%d,%d)
230 Password changed okay.
230 Switching to SYSTEM MAINTENANCE mode.
230 User logged in, proceed.
230 User logged in.
231 Switching to GROUP MAINTENANCE mode.
232 Switching to DOMAIN MAINTENANCE mode.
233 Switching to READ-ONLY MAINTENANCE mode.
233 User logged in, PASSWORD EXPIRED - please change before proceeding.
234 AUTH command OK. Already have SSL connection.
234 AUTH command OK. Initializing SSL connection.
250 %X
250 DELE command successful.
250 Directory changed to %s
250 End.
250 RMD command successful.
250 RNTO command successful.
250-Listing %s
253 Attributes changed okay.
253 Date/time changed okay.
257 "%s" directory created.
257 "%s" is current directory.
321 Transferred %I64d Bytes.
331 Response to otp-md%d %u %s required for skey.
331 User name okay, need password.
331 User name okay, please send complete E-mail address as password.
350 File or directory exists, ready for destination name
350 Restarting at %I64d. Send STORE or RETRIEVE.
421 Data connection closed (SSL/TLS negotiation failed).
421 Service closing control connection.
425 Cannot open data connection.
425 Cannot open data connection.
425 Cannot open data connection.
425 Try later, data connection in use.
425 Try later, data connection in use.
425 Try later, data connection in use.
425 Try later, out of network sockets.
425 Try later, out of network sockets.
425 Try later, out of network sockets.
425 Unable to listen, too many pending PASV requests from same client IP.
425 Unable to set up passive listening socket.
426 Data connection closed, cannot read file %s.
426 Data connection closed, cannot write file %s - disk full?
426 Data connection closed, error compressing data stream.
426 Data connection closed, error decompressing data stream.
426 Data connection closed, file transfer %s aborted by client.
426 Data connection closed, file transfer %s aborted.
426 Data connection closed, receive file %s aborted.
426 Data connection closed, transfer aborted.
426 Transfer aborted.
431 Account temporarily locked for other user, please try later.
431 Password not changed, no match for old password.
431 Unable to negotiate secure command connection.
432 Password not changed, new password should be at least %d characters in length.
432 Password not changed, new password should contain at least one upper-case character and symbol
432 Password not changed, old and new passwords cannot be identical.
450 Cannot open file %s for reading.
452 Sorry, insufficient disk quota - receive file %s aborted.
500 '%s': command not understood.
501 %s: Not a directory.
501 Cannot EXEC command line (error=%u).
501 Invalid MLST options
501 Invalid option.
501 Not enough space, only %I64d Bytes available on drive %s
501 Permission denied.
501 SITE option not supported.
501 Syntax error in parameters or arguments.
501 Syntax error in parameters or arguments.
501 Syntax error in parameters or arguments.
501 Syntax error in parameters or arguments.
501 Syntax error in parameters or arguments.
501 Syntax error in parameters or arguments.
501 Syntax error in parameters or arguments.
501 Syntax error in parameters or arguments.
501 Syntax error in parameters or arguments.
501 Syntax error in parameters or arguments.
501 Syntax error in parameters or arguments.
501 Syntax error in parameters or arguments.
501 Syntax error in parameters or arguments.
501 Syntax error in parameters or arguments.
501 Syntax error in parameters or arguments.
501 Syntax error in parameters or arguments.
501 Syntax error in parameters or arguments.
501 Syntax error in parameters or arguments.
501 Syntax error in parameters or arguments.
501 Wildcards not allowed.
502 Syntax error - use SITE PSWD "<oldpassword>" "<newpassword>".
503 Bad sequence of commands.
503 Bad sequence of commands.
503 Secure command connection required prior to PBSZ command.
503 Secure command connection required prior to PROT command.
504 Command not implemented for that parameter.
504 Command not implemented for that parameter.
504 Command not implemented for that parameter.
504 Unknown security mechanism.
510 Cannot determine server time zone.
521 Data connection cannot be opened with this PROT setting.
522 SSL/TLS lib refuses to initiate secure data connection.
530 Cannot change Anonymous password.
530 Cannot change password.
530 Not logged in, cannot find home directory.
530 Not logged in, home directory does not exist.
530 Not logged in, need secure connection.
530 Not logged in, only %d sessions from same IP allowed concurrently.
530 Not logged in, only one session from same IP allowed at a time.
530 Not logged in, too many tries with incorrect password.
530 Not logged in, unauthorized IP address.
530 Not logged in, use real E-mail address as password.
530 Not logged in.
530 Not logged in.
530 Not logged in.
530 Only client IP address allowed for PORT command.
530 Only client IP address allowed to connect to PASV socket.
530 PASSWORD EXPIRED - please change password before proceeding.
530 Port number has to be between 1024 and 65535.
530 Sorry, no ANONYMOUS access allowed.
531 SSL/TLS lib refuses to initiate secure command connection.
533 SSL command connection required prior to CCC command.
534 Invalid option. Secure data connection required for implicit SFTP.
534 Invalid option. Secure data connection required for implicit SFTP.
550 %s: Cannot create file.
550 %s: Cannot delete directory.
550 %s: Cannot delete file.
550 %s: Cannot determine date/time.
550 %s: Failed to create.
550 %s: No such file or directory.
550 %s: No such file or directory.
550 %s: No such file or directory.
550 %s: No such file or directory.
550 %s: No such file or directory.
550 %s: No such file or directory.
550 %s: No such file or directory.
550 %s: No such file or directory.
550 %s: No such file.
550 %s: No such file.
550 %s: Permission denied.
550 %s: Permission denied.
550 %s: Permission denied.
550 Cannot change path to a port.
550 Cannot create a port.
550 Cannot create INDEX for ports.
550 Cannot create unique file name.
550 Cannot delete a port.
550 Cannot delete account home directory.
550 Cannot determine date/time for a port.
550 Cannot determine size of a port.
550 Cannot EXEC a port.
550 Cannot list port.
550 Cannot position file at requested starting point.
550 Cannot read requested number of bytes from file.
550 Cannot remove a port.
550 Cannot rename to a port.
550 Cannot RESTart at any position while APPEnding to a file.
550 Cannot RESTart beyond end-of-file.
550 Cannot RESTart in a (new) unique zero-length file.
550 Cannot RESTart in a new (zero-length) file.
550 File date/time cannot be set to future.
550 File transfer not allowed, server stop is pending.
550 File transfers not allowed, server stop is pending.
550 MDTM cannot change date/time on this server.
550 No files found.
550 No maintenance manager client.
550 Passive mode not allowed on this server.
550 Permission denied
550 Permission denied.
550 Permission denied.
550 Permission denied.
550 Permission denied.
550 Permission denied.
550 Permission denied.
550 Permission denied.
550 Permission denied.
550 Permission denied.
550 Permission denied.
550 Sorry, insufficient credit for download - upload first.
550 Sorry, maximum number of GETs reached for this session.
550 Sorry, maximum number of PUTs reached for this session.
553 %s: Cannot change attributes.
553 %s: Cannot change date/time.
553 %s: Unable to rename file or directory.
553 Server Edition does not support remote administration.
有时ftp上传，下载时，总是连接出错，无外乎以下原因，仅供参考：
Serv-U BBSFTP 提示信息详解
1。 550 Not enouth credit to download .(bbsftp v2.6CE)
该提示信息一般在下载文件时出现。该提示表示您当前的下载流量不够。
2。530 Not logged in.(bbsftp v2.6CE)[FTP<202.15.29.29:21> User<rick> DB-FtpUserDown]
该提示信息一般在登录失败时出现。该提示表示用户 rick 在FTP 202.15.29.29:21 中不存在.
3。530 Not logged in, unauthorized IP address.(bbsftp v2.6CE)
表示IP地址未授权,包流量用户或包时间用户一般修改允许登录的IP地址范围后就可以登录了.
公共帐号,首先需要进行购买,才能登录.否则也会有这个提示信息.这样做是为了防止公共帐号被盗连.
4。530 Not logged in.(bbsftp v2.6CE)[BadPassword][3]
这个提示信息很明确了，密码错误。
5。530 Not logged in.(bbsftp v2.6CE)[UserDBError-FTP_USERS]
出现这个提示一般是参数设置错了，如果没有定制过数据库视图FTP_USERS，请在设置中 将是否使用数据视图设置为不使用。
6。530 Not logged in.(bbsftp v2.6CE)[UserDBError-FtpUserDown]
出现这个错误一般是数据库出问题了，可能是mysql字符集设置导致的，如果是免费版的bbsftp，还可能是mysql的优化设置导致的。
7。421 Your Account Is Expired!(bbsftp v2.6CE)
这个提示信息一般在用户登录时出现。意思是说该账号已过期。
流量购买账号，遇到这个错误信息，一般在论坛上更新一下自己的账号信息就可以了（在购买界面进行一次购买操作）。
时间购买账号，那就需要在论坛上购买账号的使用时间了。
公共账号密码，很少遇到这种提示，如果遇到这个提示信息，表示公共账号刚好多了密码更新时间了，这时之前的购买记录都会被清空，您需要重新购买公共账号和密码才能登录。
8。421 Your Account Is Disabled!(bbsftp v2.6CE)
这个信息一般在用户登录时出现，表示该账号被禁用了。只能联系管理员解决了
9。530 Not logged in, home directory does not exist.(bbsftp v2.6CE)
一般在用户登录时出现. 意思是说用户的根目录不存在.
仔细检查一下这个用户,看看他 对应的角色是否已经配置了. 如果角色不存在显然是有问题的.
然后检查其对应角色里面的 FTP根目录的设置, 看看该设置填的路径在 ftp服务器上是否存在.
如果存在的一般是没有问题的. 要注意一下三点:
1 修改角色设置后要重启servu才会生效.
2 如果该路径在ntfs格式的磁盘上,要保证ftp服务器有权限 访问这个路径.
3 如果设置了本地目录安全参数. 该路径必须是在安全目录设置的路径范围内.
10。 550 Permission denied
一般是路径访问规则的权限设置不正确，
首先检查用户对应的角色名，
然后检查角色的设置，看看是否设置了路径访问规则的组号。
再检查相应的组号的路径访问规则组，
看看是否添加了FTP根目录的访问权限。
有时候因为数据库的原因导致中文字符错误，可以试试用英文路径名。
注意修改这些设置需要重启servu。