Getting some weird behaviour when trying to pass slightly longer/more complex parameters.

This seems to work:

/parambuild/?REF=ABC123&SQL_Update=update%20TABLE%20set%20ACTIVE%3D0%20where%20USER%20LIKE%20%27ABC%27

but this doesn't:

/parambuild/?REF=ABC123&SQL_Update=update%20TABLE%20set%20ACTIVE%3D0%20where%20USER%20%3D%20%27ABC%27

(returns "This site can't be reached. The connection was reset.")

Curiously though, if I remove the previous equals sign (%3D) from the SQL_Update parameter, it works:

/parambuild/?REF=ABC123&SQL_Update=update%20TABLE%20set%20ACTIVE0%20where%20USER%20%3D%20%27ABC%27

However I don't think it's a "multiple equals signs" issue, as this works fine:

/parambuild/?REF=ABC123&SQL_Update=a%3Db%20%3D%20c%3Dd

Also, this one fails, even with no equals signs... but I added an underscore somewhere:

/parambuild/?REF=ABC123&SQL_Update=update%20TABLE%20set%20ACTIVE%200%20where%20USER_ID%20LIKE%20%27ABC%27

But this one with underscore works fine:

/parambuild/?REF=ABC123&SQL_Update=USER_ID%20like%20%27ABC%27

Good luck figuring out what's going on!