GSM7352S stack won't save config

Hi, we have a GSM7352S stack of 5 switches that won't let me save its config. When I go to Maintenance> Save Config and select the tick box and apply I get the following error (attached): Error! Failed to set 'Save Device Configuration with 'True'. I also tried to upload the config via Maintenance> Upload> HTTP File Upload> Test Configuration and when I click apply I get: Error! File is either empty or not found

 

The switches are on firmware version 10.0.0.53. I have tried doing this in Chrome, IE and Edge

 

The logs have these errors:

 

<13> MAR 14 11:02:06 169.254.100.100-4 CLI_WEB[132010224]: cliutil.c(2462) 2 %% Telnet Send Failed errno = 0x28. Failed to send text string to the telnet client.

<14> MAR 14 11:02:06 169.254.100.100-4 CLI_WEB[132010224]: cli_txtcfg.c(708) 1 %% Failed to create 'startup-config'

 

Telnet is enabled on the switch. I can see it has an APIPA address there but not sure what I can do to sort that. 

 

I would appreciate any help on this as we have to power down the switch at the weekend and we don't want to loose the configuraton!

 

If I can provide any more information please let me know. 

 

Thanks in advance!